code: @Deprecated
      public <I extends Request, O extends Response>
      B decorator(Class<I> requestType, Class<O> responseType, DecoratingClientFunction<I, O> decorator) {
          decoration.add(requestType, responseType, decorator);
          return self();
      }
docs: Adds the specified {@code decorator}.
  
  @param requestType the type of the {@link Request} that the {@code decorator} is interested in
  @param responseType the type of the {@link Response} that the {@code decorator} is interested in
  @param decorator the {@link DecoratingClientFunction} that intercepts an invocation
  @param <I> the {@link Request} type of the {@link Client} being decorated
  @param <O> the {@link Response} type of the {@link Client} being decorated
  
  @deprecated Use {@link #decorator(DecoratingClientFunction)} or
  {@link #rpcDecorator(DecoratingClientFunction)}.