code: boolean isFlowControlDisabled() {
      int bit = 1 << FLOW_CONTROL_OPTIONS;
      int value = (bit & set) != 0 ? values[FLOW_CONTROL_OPTIONS] : 0;
      return (value & FLOW_CONTROL_OPTIONS_DISABLED) != 0;
    }
docs: TODO: honor this setting in spdy/3 and HTTP/2.