getKeyHistoryMatcher(componentPosition) {
    if (this._componentHasUnmatchedHandlers(componentPosition)) {
      /**
       * We build the mapping between actions and their closest handlers the
       * first time the key map for the component at <tt>position</tt> is accessed.
       *
       * We must search higher than the current component for actions, as they are
       * often defined in parent components of those that ultimately define their
       * handlers.
       */
      while (this._componentListIterator.next()) {
        this._addHandlersFromComponent();
        this._addActionsFromComponent();
      }
    }

    return this._getKeyHistoryMatcher(componentPosition);
  }
The KeyHistoryMatcher for the component in a particular position
@param {number} componentPosition Position of component to find the
       KeyHistoryMatcher for
@returns {KeyHistoryMatcher} Key combination matcher that corresponds
       to the component