/**
     * Recycle instance, because they will be created many times.
     * @type {Array}
     * @name jibo.sound.SoundInstance._pool
     * @static
     * @private
     */

    /**
     * Recycle instance, because they will be created many times.
     * @method jibo.sound.SoundInstance.create
     * @static
     * @private
     */

        /**
         * The source node chain.
         * @type {ChainBuilder}
         * @name jibo.sound.SoundInstance#_chain
         * @private
         */

        /**
         * The starting time.
         * @type {int}
         * @name jibo.sound.SoundInstance#_startTime
         * @private
         */

        /**
         * true if paused.
         * @type {Boolean}
         * @name jibo.sound.SoundInstance#_paused
         * @private
         */

        /**
         * The time in milliseconds to wait.
         * @type {int}
         * @name jibo.sound.SoundInstance#_currentPosition
         * @private
         */

    /**
     * Initializes the instance.
     * @method jibo.sound.SoundInstance#init
     * @private
     */

    /**
     * Stops the instance.
     * @method jibo.sound.SoundInstance#stop
     */

    /**
     * Plays the sound.
     * @method jibo.sound.SoundInstance#play
     * @param {Number} [offset=0] Number of seconds to offset playing.
     */

    /**
     * Pauses the sound.
     * @type {Boolean}
     * @name jibo.sound.SoundInstance#paused
     */

    /**
     * Callback when completed.
     * @method jibo.sound.SoundInstance#_onComplete
     * @private
     */

    /**
     * Don't use after this.
     * @method jibo.sound.SoundInstance#destroy
     */

    /**
     * To string method for instance.
     * @method SoundInstance#toString
     * @return {String} The string representation of instance.
     * @private
     */