Fix build warnings about nullability.

SignalServiceKit/src/Network/API/Requests/TSRequest.h

@@ -1,7 +1,9 @@
 //
-//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
+//  Copyright (c) 2019 Open Whisper Systems. All rights reserved.
 //
 
+NS_ASSUME_NONNULL_BEGIN
+
 @class SMKUDAccessKey;
 
 @interface TSRequest : NSMutableURLRequest
@@ -30,3 +32,5 @@
                     parameters:(nullable NSDictionary<NSString *, id> *)parameters;
 
 @end
+
+NS_ASSUME_NONNULL_END

SignalServiceKit/src/Network/API/Requests/TSRequest.m

@@ -1,5 +1,5 @@
 //
-//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
+//  Copyright (c) 2019 Open Whisper Systems. All rights reserved.
 //
 
 #import "TSRequest.h"
@@ -8,6 +8,8 @@
 #import <SignalCoreKit/NSData+OWS.h>
 #import <SignalMetadataKit/SignalMetadataKit-Swift.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 @implementation TSRequest
 
 @synthesize authUsername = _authUsername;
@@ -94,7 +96,7 @@
     }
 }
 
-- (NSString *)authUsername
+- (nullable NSString *)authUsername
 {
     OWSAssertDebug(self.shouldHaveAuthorizationHeaders);
 
@@ -103,7 +105,7 @@
     }
 }
 
-- (NSString *)authPassword
+- (nullable NSString *)authPassword
 {
     OWSAssertDebug(self.shouldHaveAuthorizationHeaders);
 
@@ -113,3 +115,5 @@
 }
 
 @end
+
+NS_ASSUME_NONNULL_END

SignalServiceKit/src/Util/NSData+Image.h

@@ -1,7 +1,9 @@
 //
-//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
+//  Copyright (c) 2019 Open Whisper Systems. All rights reserved.
 //
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface NSData (Image)
 
 // If mimeType is non-nil, we ensure that the magic numbers agree with the
@@ -19,3 +21,5 @@
 + (BOOL)hasAlphaForValidImageFilePath:(NSString *)filePath;
 
 @end
+
+NS_ASSUME_NONNULL_END

SignalServiceKit/src/Util/NSData+Image.m

@@ -1,5 +1,5 @@
 //
-//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
+//  Copyright (c) 2019 Open Whisper Systems. All rights reserved.
 //
 
 #import "NSData+Image.h"
@@ -8,6 +8,8 @@
 #import <AVFoundation/AVFoundation.h>
 #import <SignalServiceKit/SignalServiceKit-Swift.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 typedef NS_ENUM(NSInteger, ImageFormat) {
     ImageFormat_Unknown,
     ImageFormat_Png,
@@ -403,3 +405,5 @@ typedef NS_ENUM(NSInteger, ImageFormat) {
 }
 
 @end
+
+NS_ASSUME_NONNULL_END