fixup

Author: ronag

lib/stream.js

@@ -56,6 +56,7 @@ Stream.isDestroyed = utils.isDestroyed;
 Stream.isDisturbed = utils.isDisturbed;
 Stream.isErrored = utils.isErrored;
 Stream.isReadable = utils.isReadable;
+Stream.isWritable = utils.isWritable;
 
 Stream.kIsDestroyed = utils.kIsDestroyed;
 Stream.kIsErrored = utils.kIsErrored;