Separate GRXForwardingWriter, delete the protocol
diff --git a/src/objective-c/RxLibrary/GRXWriter.h b/src/objective-c/RxLibrary/GRXWriter.h
index dcf44e3..5d6e1a4 100644
--- a/src/objective-c/RxLibrary/GRXWriter.h
+++ b/src/objective-c/RxLibrary/GRXWriter.h
@@ -85,7 +85,7 @@
// Unless otherwise indicated by a conforming class, no messages should be sent
// concurrently to a GRXWriter. I.e., conforming classes aren't required to
// be thread-safe.
-@protocol GRXWriter <NSObject>
+@interface GRXWriter : NSObject
// This property can be used to query the current state of the writer, which
// determines how it might currently use its writeable. Some state transitions can
@@ -116,12 +116,3 @@
// can't remember the details in the presence of concurrency.
- (void)finishWithError:(NSError *)errorOrNil;
@end
-
-// A "proxy" class that simply forwards values, completion, and errors from its
-// input writer to its writeable.
-// It is useful as a superclass for pipes that act as a transformation of their
-// input writer, and for classes that represent objects with input and
-// output sequences of values, like an RPC.
-@interface GRXWriter : NSObject<GRXWriter>
-- (instancetype)initWithWriter:(id<GRXWriter>)writer NS_DESIGNATED_INITIALIZER;
-@end