/**
 * @class Ext.draw.gradient.Radial
 * @extend Ext.draw.gradient.Gradient
 *
 * Radial gradient.
 *
 *     @example
 *     Ext.create({
 *        xtype: 'draw', 
 *        renderTo: document.body,
 *        width: 600,
 *        height: 400,
 *        sprites: [{
 *            type: 'circle',
 *            cx: 100,
 *            cy: 100,
 *            r: 100,
 *            fillStyle: {
 *                type: 'radial',
 *                start: {
 *                    x: 0,
 *                    y: 0,
 *                    r: 0
 *                },
 *                end: {
 *                    x: 0,
 *                    y: 0,
 *                    r: 1
 *                },
 *                stops: [{
 *                    offset: 0,
 *                    color: '#90BCC9'
 *                }, {
 *                    offset: 1,
 *                    color: '#1F6D91'
 *                }]
 *            }
 *        }]
 *     });
 */
 
/**
 * @cfg {Object} start 
 * The starting circle of the gradient.
 */
 
/**
 * @cfg {Object} end 
 * The ending circle of the gradient.
 */