/**
     * Jibo's emotion has changed. Gives the last available emotion.
     * @type {Event<jibo.emotion.Emotion>}
     * @name jibo.emotion.EmotionEvents#emotionChanged
     */

/**
 * @class EmotionSystem
 * @description The entire Emotion System and management of Jibo's internal emotional state,
 * including the Appraisal System, Expression System, Sensory System, and Emotional Space.
 * @memberof jibo.emotion
 * @private
 * @internal
 */

    /**
     * This is a record of all emotional events Jibo is aware of, containing Sensor data, appraisal rules
     * the previous and new emotional states, and what expressions if any occurred as a result
     * @type {Array<jibo.emotion.emotionTrace>}
     * @name jibo.emotion.EmotionSystem#history
     * @private
     */

    /**
     * The emotional events of the EmotionSystem
     * @type {jibo.emotion.EmotionEvents}
     * @name jibo.emotion.EmotionSystem#events
     * @private
     */

    /**
     * Emotion Wrappers
     * @type {jibo.emotion.Emotion[]}
     * @name jibo.emotion.EmotionSystem#emotions
     * @private
     */

    /**
     * Provides default rules given a sensory system
     * @type {jibo.emotion.appraisal.AppraisalRule[]}
     * @name jibo.emotion.EmotionSystem#rules
     * @private
     */

    /**
     * The various sensors used to input emotional data and affect Jibo's
     * emotional landscape.
     * @const {Array.<Sensor>}
     * @memberOf jibo.emotion
     * @private
     */

    /**
     * This should not be a part of the external API
     * @internal
     * @int-docs
     * @private
     */

    /**
     * The current emotional P.A.D. space that represents what Jibo is feeling
     * in relation to his other possible emotional states.
     * @type {jibo.emotion.EmotionSpace}
     * @private
     * @memberOf jibo.emotion
     */

    /**
     * The sensory system that aggregates all sensors and provides a single
     * point of interactions for events.
     * @type {jibo.emotion.SensorySystem}
     * @private
     * @memberOf jibo.emotion
     */

    /**
     * The perceptual appraisal system that interprets sensory input that
     * affects Jibo.
     * @type {jibo.emotion.AppraisalSystem}
     * @private
     * @memberOf jibo.emotion
     */

    /**
     * The system that maps emotions and emotional impacts to actions via the Action System plugin
     * @type {jibo.emotion.ExpressionSystem}
     * @private
     * @memberOf jibo.emotion
     */

    /**
     * Map of expression names to Expression objects
     * @type {Map<jibo.emotion.EmotionName, jibo.emotion.EmotionalExpression>}
     * @private
     * @memberOf jibo.emotion
     */