Add documentation

Author: renefloor

packages/camera/camera/example/ios/RunnerTests/CameraMethodChannelTests.m

@@ -17,11 +17,18 @@ @interface MockFLTThreadSafeFlutterResult : FLTThreadSafeFlutterResult
 @end
 
 @implementation MockFLTThreadSafeFlutterResult
+/**
+ Initialize with a notification center.
+ */
 - (id)initWithNotificationCenter:(NSNotificationCenter *)notificationCenter {
   self = [super init];
   _notificationCenter = notificationCenter;
   return self;
 }
+
+/**
+ Called when result is successful. Sends "successWithData" to the notification center.
+ */
 - (void)successWithData:(id)data {
   _receivedResult = data;
   [self->_notificationCenter postNotificationName:@"successWithData" object:nil];

packages/camera/camera/ios/Classes/FLTThreadSafeFlutterResult.h

@@ -4,13 +4,43 @@
 
 #import <Flutter/Flutter.h>
 
+/**
+ Wrapper object that always delivers the result on the main thread.
+ */
 @interface FLTThreadSafeFlutterResult : NSObject
+
+/**
+ Initialize with a FlutterResult object.
+ @param result The FlutterResult object that the result will be given to.
+ */
 - (id _Nonnull)initWithResult:(FlutterResult _Nonnull)result;
+
+/**
+ Send a successful result without any data.
+ */
 - (void)success;
+
+/**
+ Send a successful result with data.
+ @param data Result data that is send to the Flutter Dart side.
+ */
 - (void)successWithData:(id _Nonnull)data;
+
+/**
+ Send an error as result
+ @param error Error that will be send as FlutterError.
+ */
 - (void)error:(NSError* _Nonnull)error;
-- (void)notImplemented;
+
+/**
+ Send a FlutterError as result.
+ */
 - (void)errorWithCode:(NSString* _Nonnull)code
               message:(NSString* _Nullable)message
               details:(id _Nullable)details;
+
+/**
+ Send FlutterMethodNotImplemented as result.
+ */
+- (void)notImplemented;
 @end