    /**
     * @private
     */
    Ext.define('Ext.fx.easing.EaseIn', {
        extend: 'Ext.fx.easing.Linear',

        alias: 'easing.ease-in',

        config: {
            exponent: 4,
            duration: 1500
        },

        getValue: function() {
            var deltaTime = Ext.Date.now() - this.getStartTime(),
                duration = this.getDuration(),
                startValue = this.getStartValue(),
                endValue = this.getEndValue(),
                distance = this.distance,
                theta = deltaTime / duration,
                thetaEnd = Math.pow(theta, this.getExponent()),
                currentValue = startValue + (thetaEnd * distance);

            if (deltaTime >= duration) {
                this.isEnded = true;
                return endValue;
            }

            return currentValue;
        }
    });