ignoreEvent(event) {
    this._ignoreEvent = true;

    if (this.isIgnoringEvent() && Configuration.option('stopEventPropagationAfterIgnoring')) {
      this.logger.debug(
        this.logger.keyEventPrefix(this._componentId),
        'Stopping further event propagation.'
      );

      this.stop(event);
      this.finishPropagationStep();

      return true;
    }

    return false;
  }
Record that an event is being ignored for the rest of its propagation and, if
enabled, stop it from further propagation entirely.
@param {SyntheticKeyboardEvent} event Event to ignore
@returns {boolean} true if the event was stopped from further propagation,
         otherwise false.