    /**
     * @private
     */
    Ext.define('Ext.fx.easing.Bounce', {

        extend: 'Ext.fx.easing.Abstract',

        config: {
            springTension: 0.3,
            acceleration: 30,
            startVelocity: 0
        },

        getValue: function() {
            var deltaTime = Ext.Date.now() - this.getStartTime(),
                theta = (deltaTime / this.getAcceleration()),
                powTime = theta * Math.pow(Math.E, -this.getSpringTension() * theta);

            return this.getStartValue() + (this.getStartVelocity() * powTime);
        }
    });