这是一个swing的练习，实现了一个变色功能和贴图功能-This is a practice swing to achieve a color features and texture features

利用按钮在面板中画圆，并能改变圆形的颜色-Create an application AddCircles that displays a panel. This panel will contain two buttons (one for red and one for blue). When the user clicks on a button, change a variable called currentColor t