* This layout manages multiple child Components, each fitted to the Container, where only a single child Component can be
* visible at any given time. This layout style is most commonly used for wizards, tab implementations, etc.
* This class is intended to be extended or created via the layout:'card' {@link Ext.container.Container#layout} config,
* and should generally not need to be created directly via the new keyword.
*
* The CardLayout's focal method is {@link #setActiveItem}. Since only one panel is displayed at a time,
* This layout manages multiple child Components, each fitted to the Container, where only a single child Component can be
* visible at any given time. This layout style is most commonly used for wizards, tab implementations, etc.
* This class is intended to be extended or created via the layout:'card' {@link Ext.container.Container#layout} config,
* and should generally not need to be created directly via the new keyword.
*
* The CardLayout's focal method is {@link #setActiveItem}. Since only one panel is displayed at a time,