@ExperimentalApi("https://github.com/grpc/grpc-java/issues/1869")
  public final <T> S withOption(CallOptions.Key<T> key, T value) {
    return build(channel, callOptions.withOption(key, value));
  }
@ ExperimentalApi ( "https://github.com/grpc/grpc-java/issues/1869" ) public final < T > S withOption ( CallOptions . Key < T > key , T value ) { return build ( channel , callOptions . withOption ( key , value ) ) ; }
Sets a custom option to be passed to client interceptors on the channel
{@link io.grpc.ClientInterceptor} via the CallOptions parameter.

@since 1.0.0
@param key the option being set
@param value the value for the key