constructor() {
    /**
     * List of ComponentOptions for the actions registered by each hot keys component.
     * @type {ComponentOptions[]}
     */
    this._list = [];

    /**
     * Dictionary mapping the ids of the components defining actions, and their
     * position in the list.
     * @type {Object.<ComponentId, Number>}
     */
    this._idToIndex = {};

    /**
     * Counter for the length of the longest sequence currently enabled.
     * @type {number}
     */
    this.longestSequence = 1;

    /**
     * The id of the component with the longest key sequence
     * @type {ComponentId}
     */
    this._longestSequenceComponentId = null;

    /**
     * Record of whether at least one keymap is bound to each event type (keydown,
     * keypress or keyup)
     * @type {KeyEvent}
     */
    this._keyMapEventRecord = KeyEventStateArrayManager.newRecord();
  }
List of component options that define the application's currently enabled key
maps and handlers, starting from the inner-most (most deeply nested) component,
that is closest to the DOM element currently in focus, and ending with the options
of the root hotkeys component.
@class