This property controls the minimum extent of the extra space in the splitter's parent. Typically, this is the control which is a sibling to the UltraSplitter and is docked to Fill.
The extent here refers to the width of the control when the splitter is docked left or right and the height of the control when the splitter is docked top or bottom.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2