Update type names and comments

Advanced NSOperations.xcodeproj/project.pbxproj

@@ -19,13 +19,13 @@
 		553F50161B08E98A005F991E /* LoadModelOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 553F50151B08E98A005F991E /* LoadModelOperation.swift */; };
 		55817C3A1B18FDF8001C0CE2 /* EarthquakeOperationQueue.swift in Sources */ = {isa = PBXBuildFile; fileRef = 551B9C061AEB2D7800302388 /* EarthquakeOperationQueue.swift */; };
 		55817C3B1B18FDF8001C0CE2 /* ExclusivityController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 55CD4D201AF5C05300E3A9E3 /* ExclusivityController.swift */; };
-		55817C3D1B18FDF8001C0CE2 /* EarthquakeBlockOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 55857B3A1AF20DE800219D5A /* EarthquakeBlockOperation.swift */; };
 		55817C3C1B18FDF8001C0CE2 /* EarthquakeOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 551B9C021AEB1CA900302388 /* EarthquakeOperation.swift */; };
+		55817C3D1B18FDF8001C0CE2 /* EarthquakeBlockOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 55857B3A1AF20DE800219D5A /* EarthquakeBlockOperation.swift */; };
 		55817C3E1B18FDF8001C0CE2 /* GroupOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 55727FB11AF2798C00EC6916 /* GroupOperation.swift */; };
 		55817C3F1B18FDF8001C0CE2 /* URLSessionTaskOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 55727FB91AF2849E00EC6916 /* URLSessionTaskOperation.swift */; };
 		55817C401B18FDF8001C0CE2 /* LocationOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 553F50031B07FB5E005F991E /* LocationOperation.swift */; };
 		55817C411B18FDF8001C0CE2 /* DelayOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 553F50131B0832D2005F991E /* DelayOperation.swift */; };
-		55817C421B18FDF8001C0CE2 /* OperationObserver.swift in Sources */ = {isa = PBXBuildFile; fileRef = 553F50051B081760005F991E /* OperationObserver.swift */; };
+		55817C421B18FDF8001C0CE2 /* EarthquakeOperationObserver.swift in Sources */ = {isa = PBXBuildFile; fileRef = 553F50051B081760005F991E /* EarthquakeOperationObserver.swift */; };
 		55817C431B18FDF8001C0CE2 /* BlockObserver.swift in Sources */ = {isa = PBXBuildFile; fileRef = 553F50081B0817D2005F991E /* BlockObserver.swift */; };
 		55817C441B18FDF8001C0CE2 /* TimeoutObserver.swift in Sources */ = {isa = PBXBuildFile; fileRef = 55AD643C1B128CC3000EF5CB /* TimeoutObserver.swift */; };
 		55817C451B18FDF8001C0CE2 /* OperationErrors.swift in Sources */ = {isa = PBXBuildFile; fileRef = 553F2D651B00041100BF4093 /* OperationErrors.swift */; };
@@ -96,7 +96,7 @@
 		553C5AC61AF6D2EB002FC47A /* HealthCondition.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = HealthCondition.swift; sourceTree = "<group>"; };
 		553F2D651B00041100BF4093 /* OperationErrors.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = OperationErrors.swift; sourceTree = "<group>"; };
 		553F50031B07FB5E005F991E /* LocationOperation.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = LocationOperation.swift; sourceTree = "<group>"; };
-		553F50051B081760005F991E /* OperationObserver.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = OperationObserver.swift; sourceTree = "<group>"; };
+		553F50051B081760005F991E /* EarthquakeOperationObserver.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = EarthquakeOperationObserver.swift; sourceTree = "<group>"; };
 		553F50081B0817D2005F991E /* BlockObserver.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = BlockObserver.swift; sourceTree = "<group>"; };
 		553F500E1B081A9D005F991E /* NetworkObserver.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = NetworkObserver.swift; sourceTree = "<group>"; };
 		553F50101B082BCF005F991E /* BackgroundObserver.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = BackgroundObserver.swift; sourceTree = "<group>"; };
@@ -227,7 +227,7 @@
 		553F50071B0817BB005F991E /* Observers */ = {
 			isa = PBXGroup;
 			children = (
-				553F50051B081760005F991E /* OperationObserver.swift */,
+				553F50051B081760005F991E /* EarthquakeOperationObserver.swift */,
 				553F50081B0817D2005F991E /* BlockObserver.swift */,
 				55AD643C1B128CC3000EF5CB /* TimeoutObserver.swift */,
 			);
@@ -417,7 +417,7 @@
 				55817C3E1B18FDF8001C0CE2 /* GroupOperation.swift in Sources */,
 				55817C491B18FDF8001C0CE2 /* NoCancelledDependencies.swift in Sources */,
 				55817C581B18FDF8001C0CE2 /* UIUserNotifications+Operations.swift in Sources */,
-				55817C421B18FDF8001C0CE2 /* OperationObserver.swift in Sources */,
+				55817C421B18FDF8001C0CE2 /* EarthquakeOperationObserver.swift in Sources */,
 				5521B4821B700C87007089CE /* NSLock+Operations.swift in Sources */,
 				553F500F1B081A9D005F991E /* NetworkObserver.swift in Sources */,
 				55817C551B18FDF8001C0CE2 /* Dictionary+Operations.swift in Sources */,

Earthquakes/BackgroundObserver.swift

@@ -9,13 +9,13 @@ Contains the code related to automatic background tasks
 import UIKit
 
 /**
-    `BackgroundObserver` is an `OperationObserver` that will automatically begin
+    `BackgroundObserver` is an `EarthquakeOperationObserver` that will
-    and end a background task if the application transitions to the background.
+    automatically begin and end a background task if the application transitions to the
-    This would be useful if you had a vital `Operation` whose execution *must* complete,
+    background. This would be useful if you had a vital `EarthquakeOperation`
-    regardless of the activation state of the app. Some kinds network connections
+    whose execution *must* complete, regardless of the activation state of the app.
-    may fall in to this category, for example.
+    Some kinds network connections may fall in to this category, for example.
 */
-class BackgroundObserver: NSObject, OperationObserver {
+class BackgroundObserver: NSObject, EarthquakeOperationObserver {
     // MARK: Properties
 
     private var identifier = UIBackgroundTaskIdentifier.invalid

Earthquakes/EarthquakeTableViewController.swift

@@ -89,7 +89,7 @@ class EarthquakeTableViewController: UITableViewController {
 
         /*
             We could present the share sheet manually, but by putting it inside
-            an `Operation`, we can make it mutually exclusive with other operations
+            an `EarthquakeOperation`, we can make it mutually exclusive with other operations
             that modify the view controller hierarchy.
         */
         let shareOperation = EarthquakeBlockOperation { (continuation: @escaping () -> Void) in

Earthquakes/GetEarthquakesOperation.swift

@@ -8,7 +8,7 @@ This file sets up the operations to download and parse earthquake data. It will
 
 import CoreData
 
-/// A composite `Operation` to both download and parse earthquake data.
+/// A composite `EarthquakeOperation` to both download and parse earthquake data.
 class GetEarthquakesOperation: GroupOperation {
     // MARK: Properties
     

Earthquakes/LoadModelOperation.swift

@@ -9,7 +9,7 @@ This file contains the code to create the Core Data stack.
 import CoreData
 
 /**
-    An `Operation` subclass that loads the Core Data stack. If this operation fails,
+    An `EarthquakeOperation` subclass that loads the Core Data stack. If this operation fails,
     it will produce an `AlertOperation` that will offer to retry the operation.
 */
 class LoadModelOperation: EarthquakeOperation {

Earthquakes/MoreInformationOperation.swift

@@ -9,7 +9,7 @@ This file contains the code to present more information about an earthquake as a
 import Foundation
 import SafariServices
 
-/// An `Operation` to display an `URL` in an app-modal `SFSafariViewController`.
+/// An `EarthquakeOperation` to display an `URL` in an app-modal `SFSafariViewController`.
 class MoreInformationOperation: EarthquakeOperation {
     // MARK: Properties
 

Earthquakes/NetworkObserver.swift

@@ -9,10 +9,11 @@ Contains the code to manage the visibility of the network activity indicator
 import UIKit
 
 /**
-    An `OperationObserver` that will cause the network activity indicator to appear
+    An `EarthquakeOperationObserver` that will cause the network activity
-    as long as the `Operation` to which it is attached is executing.
+    indicator to appear as long as the `EarthquakeOperation` to which it is
+    attached is executing.
 */
-struct NetworkObserver: OperationObserver {
+struct NetworkObserver: EarthquakeOperationObserver {
     // MARK: Initilization
 
     init() { }

Earthquakes/Operations/BlockObserver.swift

@@ -10,9 +10,9 @@ import Foundation
 
 /**
     The `BlockObserver` is a way to attach arbitrary blocks to significant events
-    in an `Operation`'s lifecycle.
+    in an `EarthquakeOperation`'s lifecycle.
 */
-struct BlockObserver: OperationObserver {
+struct BlockObserver: EarthquakeOperationObserver {
     // MARK: Properties
     
     private let startHandler: ((EarthquakeOperation) -> Void)?

Earthquakes/Operations/CalendarCondition.swift

@@ -50,7 +50,7 @@ struct CalendarCondition: OperationCondition {
 private let SharedEventStore = EKEventStore()
 
 /**
-    A private `Operation` that will request access to the user's Calendar/Reminders,
+    A private `EarthquakeOperation` that will request access to the user's Calendar/Reminders,
     if it has not already been granted.
 */
 private class CalendarPermissionOperation: EarthquakeOperation {

Earthquakes/Operations/DelayOperation.swift

@@ -9,15 +9,15 @@ This file shows how to make an operation that efficiently waits.
 import Foundation
 
 /**
-    `DelayOperation` is an `Operation` that will simply wait for a given time
+    `DelayOperation` is an `EarthquakeOperation` that will simply wait for a
-    interval, or until a specific `NSDate`.
+    given time interval, or until a specific `Date`.
 
     It is important to note that this operation does **not** use the `sleep()`
     function, since that is inefficient and blocks the thread on which it is called.
-    Instead, this operation uses `dispatch_after` to know when the appropriate amount
+    Instead, this operation uses `DispatchQueue.asyncAfter` to know
-    of time has passed.
+    when the appropriate amount of time has passed.
 
-    If the interval is negative, or the `NSDate` is in the past, then this operation
+    If the interval is negative, or the `Date` is in the past, then this operation
     immediately finishes.
 */
 class DelayOperation: EarthquakeOperation {

Earthquakes/Operations/EarthquakeBlockOperation.swift

@@ -3,7 +3,7 @@ Copyright (C) 2015 Apple Inc. All Rights Reserved.
 See LICENSE.txt for this sample’s licensing information
 
 Abstract:
-This code shows how to create a simple subclass of Operation.
+This code shows how to create a simple subclass of EarthquakeOperation.
 */
 
 import Foundation

Earthquakes/Operations/EarthquakeOperation.swift

@@ -3,13 +3,13 @@ Copyright (C) 2015 Apple Inc. All Rights Reserved.
 See LICENSE.txt for this sample’s licensing information
 
 Abstract:
-This file contains the foundational subclass of NSOperation.
+This file contains the foundational subclass of Operation.
 */
 
 import Foundation
 
 /**
-    The subclass of `NSOperation` from which all other operations should be derived.
+    The subclass of `Operation` from which all other operations should be derived.
     This class adds both Conditions and Observers, which allow the operation to define
     extended readiness requirements, as well as notify many interested parties
     about interesting operation state changes
@@ -29,31 +29,31 @@ class EarthquakeOperation: Operation {
     // MARK: State Management
     
     fileprivate enum State: Int, Comparable {
-        /// The initial state of an `Operation`.
+        /// The initial state of an `EarthquakeOperation`.
         case Initialized
         
-        /// The `Operation` is ready to begin evaluating conditions.
+        /// The `EarthquakeOperation` is ready to begin evaluating conditions.
         case Pending
         
-        /// The `Operation` is evaluating conditions.
+        /// The `EarthquakeOperation` is evaluating conditions.
         case EvaluatingConditions
         
         /**
-            The `Operation`'s conditions have all been satisfied, and it is ready
+            The `EarthquakeOperation`'s conditions have all been satisfied, and it is ready
             to execute.
         */
         case Ready
         
-        /// The `Operation` is executing.
+        /// The `EarthquakeOperation` is executing.
         case Executing
         
         /**
-            Execution of the `Operation` has finished, but it has not yet notified
+            Execution of the `EarthquakeOperation` has finished, but it has not yet notified
             the queue of this.
         */
         case Finishing
         
-        /// The `Operation` has finished executing.
+        /// The `EarthquakeOperation` has finished executing.
         case Finished
         
         func canTransitionToState(target: State) -> Bool {
@@ -79,7 +79,7 @@ class EarthquakeOperation: Operation {
     }
     
     /**
-        Indicates that the Operation can now begin to evaluate readiness conditions,
+        Indicates that the EarthquakeOperation can now begin to evaluate readiness conditions,
         if appropriate.
     */
     func willEnqueue() {
@@ -194,9 +194,9 @@ class EarthquakeOperation: Operation {
         conditions.append(condition)
     }
     
-    private(set) var observers = [OperationObserver]()
+    private(set) var observers = [EarthquakeOperationObserver]()
     
-    func addObserver(observer: OperationObserver) {
+    func addObserver(observer: EarthquakeOperationObserver) {
         assert(state < .Executing, "Cannot modify observers after execution has begun.")
         
         observers.append(observer)
@@ -211,7 +211,7 @@ class EarthquakeOperation: Operation {
     // MARK: Execution and Cancellation
     
     override final func start() {
-        // NSOperation.start() contains important logic that shouldn't be bypassed.
+        // Operation.start() contains important logic that shouldn't be bypassed.
         super.start()
         
         // If the operation has been cancelled, we still need to enter the "Finished" state.
@@ -238,12 +238,12 @@ class EarthquakeOperation: Operation {
     }
     
     /**
-        `execute()` is the entry point of execution for all `Operation` subclasses.
+        `execute()` is the entry point of execution for all `EarthquakeOperation`
-        If you subclass `Operation` and wish to customize its execution, you would
+        subclasses. If you subclass `EarthquakeOperation` and wish to customize its
-        do so by overriding the `execute()` method.
+        execution, you would do so by overriding the `execute()` method.
         
-        At some point, your `Operation` subclass must call one of the "finish"
+        At some point, your `EarthquakeOperation` subclass must call one of the
-        methods defined below; this is how you indicate that your operation has
+        "finish" methods defined below; this is how you indicate that your operation has
         finished its execution, and that operations dependent on yours can re-evaluate
         their readiness state.
     */

Earthquakes/Operations/EarthquakeOperationObserver.swift

@@ -12,16 +12,16 @@ import Foundation
     The protocol that types may implement if they wish to be notified of significant
     operation lifecycle events.
 */
-protocol OperationObserver {
+protocol EarthquakeOperationObserver {
     
-    /// Invoked immediately prior to the `Operation`'s `execute()` method.
+    /// Invoked immediately prior to the `EarthquakeOperation`'s `execute()` method.
     func operationDidStart(operation: EarthquakeOperation)
     
-    /// Invoked when `Operation.produceOperation(_:)` is executed.
+    /// Invoked when `EarthquakeOperation.produceOperation(_:)` is executed.
     func operation(operation: EarthquakeOperation, didProduceOperation newOperation: Operation)
     
     /**
-        Invoked as an `Operation` finishes, along with any errors produced during
+        Invoked as an `EarthquakeOperation` finishes, along with any errors produced during
         execution (or readiness evaluation).
     */
     func operationDidFinish(operation: EarthquakeOperation, errors: [NSError])

Earthquakes/Operations/EarthquakeOperationQueue.swift

@@ -3,20 +3,20 @@ Copyright (C) 2015 Apple Inc. All Rights Reserved.
 See LICENSE.txt for this sample’s licensing information
 
 Abstract:
-This file contains an NSOperationQueue subclass.
+This file contains an OperationQueue subclass.
 */
 
 import Foundation
 
 /**
-    The delegate of an `OperationQueue` can respond to `Operation` lifecycle
+    The delegate of an `EarthquakeOperationQueue` can respond to `EarthquakeOperation`
-    events by implementing these methods.
+    lifecycle events by implementing these methods.
 
-    In general, implementing `OperationQueueDelegate` is not necessary; you would
+    In general, implementing `EarthquakeOperationQueueDelegate` is not necessary; you would
-    want to use an `OperationObserver` instead. However, there are a couple of
+    want to use an `EarthquakeOperationObserver` instead. However, there are a couple of
-    situations where using `OperationQueueDelegate` can lead to simpler code.
+    situations where using `EarthquakeOperationQueueDelegate` can lead to simpler code.
     For example, `GroupOperation` is the delegate of its own internal
-    `OperationQueue` and uses it to manage dependencies.
+    `EarthquakeOperationQueue` and uses it to manage dependencies.
 */
 @objc protocol EarthquakeOperationQueueDelegate: NSObjectProtocol {
     @objc optional func operationQueue(operationQueue: EarthquakeOperationQueue, willAddOperation operation: Operation)
@@ -24,8 +24,8 @@ import Foundation
 }
 
 /**
-    `OperationQueue` is an `NSOperationQueue` subclass that implements a large
+    `EarthquakeOperationQueue` is an `OperationQueue` subclass that implements a large
-    number of "extra features" related to the `Operation` class:
+    number of "extra features" related to the `EarthquakeOperation` class:
     
     - Notifying a delegate of all operation completion
     - Extracting generated dependencies from operation conditions
@@ -36,7 +36,7 @@ class EarthquakeOperationQueue: OperationQueue {
     
     override func addOperation(_ operation: Operation) {
         if let op = operation as? EarthquakeOperation {
-            // Set up a `BlockObserver` to invoke the `OperationQueueDelegate` method.
+            // Set up a `BlockObserver` to invoke the `EarthquakeOperationQueueDelegate` method.
             let delegate = BlockObserver(
                 startHandler: nil,
                 produceHandler: { [weak self] in
@@ -91,10 +91,10 @@ class EarthquakeOperationQueue: OperationQueue {
         }
         else {
             /*
-                For regular `NSOperation`s, we'll manually call out to the queue's
+                For regular `EarthquakeOperation`s, we'll manually call out to the
-                delegate we don't want to just capture "operation" because that
+                queue's delegate we don't want to just capture "operation" because
-                would lead to the operation strongly referencing itself and that's
+                that would lead to the operation strongly referencing itself and
-                the pure definition of a memory leak.
+                that's the pure definition of a memory leak.
             */
             operation.addCompletionBlock { [weak self, weak operation] in
                 guard let queue = self, let operation = operation else { return }

Earthquakes/Operations/ExclusivityController.swift

@@ -10,9 +10,10 @@ import Foundation
 
 /**
     `ExclusivityController` is a singleton to keep track of all the in-flight
-    `Operation` instances that have declared themselves as requiring mutual exclusivity.
+    `EarthquakeOperation` instances that have declared themselves as requiring
-    We use a singleton because mutual exclusivity must be enforced across the entire
+    mutual exclusivity. We use a singleton because mutual exclusivity must be enforced
-    app, regardless of the `OperationQueue` on which an `Operation` was executed.
+    across the entire app, regardless of the `EarthquakeOperationQueue` on which an
+    `EarthquakeOperation` was executed.
 */
 class ExclusivityController {
     static let sharedExclusivityController = ExclusivityController()

Earthquakes/Operations/GroupOperation.swift

@@ -9,7 +9,7 @@ This file shows how operations can be composed together to form new operations.
 import Foundation
 
 /**
-    A subclass of `Operation` that executes zero or more operations as part of its
+    A subclass of `EarthquakeOperation` that executes zero or more operations as part of its
     own execution. This class of operation is very useful for abstracting several
     smaller operations into a larger operation. As an example, the `GetEarthquakesOperation`
     is composed of both a `DownloadEarthquakesOperation` and a `ParseEarthquakesOperation`.

Earthquakes/Operations/HealthCondition.swift

@@ -12,7 +12,7 @@ import HealthKit
 import UIKit
 
 /**
-    A condition to indicate an `Operation` requires access to the user's health
+    A condition to indicate an `EarthquakeOperation` requires access to the user's health
     data.
 */
 struct HealthCondition: OperationCondition {
@@ -92,7 +92,7 @@ struct HealthCondition: OperationCondition {
 }
 
 /**
-    A private `Operation` that will request access to the user's health data, if
+    A private `EarthquakeOperation` that will request access to the user's health data, if
     it has not already been granted.
 */
 private class HealthPermissionOperation: EarthquakeOperation {

Earthquakes/Operations/LocationCondition.swift

@@ -79,7 +79,7 @@ struct LocationCondition: OperationCondition {
 }
 
 /**
-    A private `Operation` that will request permission to access the user's location,
+    A private `EarthquakeOperation` that will request permission to access the user's location,
     if permission has not already been granted.
 */
 private class LocationPermissionOperation: EarthquakeOperation {

Earthquakes/Operations/LocationOperation.swift

@@ -10,10 +10,10 @@ import Foundation
 import CoreLocation
 
 /**
-    `LocationOperation` is an `Operation` subclass to do a "one-shot" request to
+    `LocationOperation` is an `EarthquakeOperation` subclass to do
-    get the user's current location, with a desired accuracy. This operation will
+    a "one-shot" request to get the user's current location, with a desired accuracy.
-    prompt for `WhenInUse` location authorization, if the app does not already
+    This operation will prompt for `WhenInUse` location authorization, if the app
-    have it.
+    does not already have it.
 */
 class LocationOperation: EarthquakeOperation, CLLocationManagerDelegate {
     // MARK: Properties

Earthquakes/Operations/NSOperation+Operations.swift

@@ -3,14 +3,14 @@ Copyright (C) 2015 Apple Inc. All Rights Reserved.
 See LICENSE.txt for this sample’s licensing information
 
 Abstract:
-A convenient extension to Foundation.NSOperation.
+A convenient extension to Foundation.Operation.
 */
 
 import Foundation
 
 extension Operation {
     /**
-        Add a completion block to be executed after the `NSOperation` enters the
+        Add a completion block to be executed after the `Operation` enters the
         "finished" state.
     */
     func addCompletionBlock(block: @escaping () -> Void) {

Earthquakes/Operations/OperationCondition.swift

@@ -3,7 +3,7 @@ Copyright (C) 2015 Apple Inc. All Rights Reserved.
 See LICENSE.txt for this sample’s licensing information
 
 Abstract:
-This file contains the fundamental logic relating to Operation conditions.
+This file contains the fundamental logic relating to EarthquakeOperation conditions.
 */
 
 import Foundation
@@ -32,9 +32,9 @@ protocol OperationCondition {
         operation is executed first. Use this method to return an operation that
         (for example) asks for permission to perform the operation
         
-        - parameter operation: The `Operation` to which the Condition has been added.
+        - Parameter operation: The `EarthquakeOperation` to which the Condition has been added.
-        - returns: An `NSOperation`, if a dependency should be automatically added. Otherwise, `nil`.
+        - Returns: An `Operation`, if a dependency should be automatically added. Otherwise, `nil`.
-        - note: Only a single operation may be returned as a dependency. If you
+        - Note: Only a single operation may be returned as a dependency. If you
             find that you need to return multiple operations, then you should be
             expressing that as multiple conditions. Alternatively, you could return
             a single `GroupOperation` that executes multiple operations internally.

Earthquakes/Operations/PhotosCondition.swift

@@ -38,7 +38,7 @@ struct PhotosCondition: OperationCondition {
 }
 
 /**
-    A private `Operation` that will request access to the user's Photos, if it
+    A private `EarthquakeOperation` that will request access to the user's Photos, if it
     has not already been granted.
 */
 private class PhotosPermissionOperation: EarthquakeOperation {

Earthquakes/Operations/RemoteNotificationCondition.swift

@@ -68,7 +68,7 @@ struct RemoteNotificationCondition: OperationCondition {
 }
 
 /**
-    A private `Operation` to request a push notification token from the `UIApplication`.
+    A private `EarthquakeOperation` to request a push notification token from the `UIApplication`.
     
     - note: This operation is used for *both* the generated dependency **and**
         condition evaluation, since there is no "easy" way to retrieve the push

Earthquakes/Operations/TimeoutObserver.swift

@@ -9,10 +9,10 @@ This file shows how to implement the OperationObserver protocol.
 import Foundation
 
 /**
-    `TimeoutObserver` is a way to make an `Operation` automatically time out and
+    `TimeoutObserver` is a way to make an `EarthquakeOperation` automatically time out and
     cancel after a specified time interval.
 */
-struct TimeoutObserver: OperationObserver {
+struct TimeoutObserver {
     // MARK: Properties
 
     static let timeoutKey = "Timeout"
@@ -24,9 +24,11 @@ struct TimeoutObserver: OperationObserver {
     init(timeout: Int) {
         self.timeout = timeout
     }
+}
 
-    // MARK: OperationObserver
+// MARK: EarthquakeOperationObserver
 
+extension TimeoutObserver: EarthquakeOperationObserver {    
     func operationDidStart(operation: EarthquakeOperation) {
         // When the operation starts, queue up a block to cause it to time out.
         DispatchQueue.global(qos: .default).asyncAfter(deadline: .now() + .seconds(timeout)) {

Earthquakes/Operations/URLSessionTaskOperation.swift

@@ -3,7 +3,7 @@ Copyright (C) 2015 Apple Inc. All Rights Reserved.
 See LICENSE.txt for this sample’s licensing information
 
 Abstract:
-Shows how to lift operation-like objects in to the NSOperation world.
+Shows how to lift operation-like objects in to the Operation world.
 */
 
 import Foundation
@@ -11,8 +11,8 @@ import Foundation
 private var URLSessionTaksOperationKVOContext = 0
 
 /**
-    `URLSessionTaskOperation` is an `Operation` that lifts an `URLSessionTask`
+    `URLSessionTaskOperation` is an `EarthquakeOperation` that lifts
-    into an operation.
+    an `URLSessionTask` into an operation.
 
     Note that this operation does not participate in any of the delegate callbacks \
     of an `URLSession`, but instead uses Key-Value-Observing to know when the

Earthquakes/Operations/UserNotificationCondition.swift

@@ -82,7 +82,7 @@ struct UserNotificationCondition: OperationCondition {
 }
 
 /**
-    A private `Operation` subclass to register a `UIUserNotificationSettings`
+    A private `EarthquakeOperation` subclass to register a `UIUserNotificationSettings`
     object with a `UIApplication`, prompting the user for permission if necessary.
 */
 private class UserNotificationPermissionOperation: EarthquakeOperation {

Earthquakes/ParseEarthquakesOperation.swift

@@ -58,7 +58,7 @@ private struct ParsedEarthquake {
     }
 }
 
-/// An `Operation` to parse earthquakes out of a downloaded feed from the USGS.
+/// An `EarthquakeOperation` to parse earthquakes out of a downloaded feed from the USGS.
 class ParseEarthquakesOperation: EarthquakeOperation {
     let cacheFile: URL
     let context: NSManagedObjectContext