code: public Observable<Void> write(Observable<WebSocketFrame> msgs, Func1<WebSocketFrame, Boolean> flushSelector) {
          return delegate.write(msgs, flushSelector);
      }
docs: On subscription of the returned {@link Observable}, writes the passed message stream on the underneath channel
  and flushes the channel, everytime, {@code flushSelector} returns {@code true} . Any writes issued before
  subscribing, will also be flushed. However, the returned {@link Observable} will not capture the result of those
  writes, i.e. if the other writes, fail and this write does not, the returned {@link Observable} will not fail.
  
  @param msgs Message stream to write.
  @param flushSelector A {@link Func1} which is invoked for every item emitted from {@code msgs}. Channel is
  flushed, iff this function returns, {@code true}.
  
  @return An {@link Observable} representing the result of this write. Every
  subscription to this {@link Observable} will write the passed messages and flush all pending writes, when the
  {@code flushSelector} returns {@code true}