If this property is set to Rectangle.Empty, then the entire chart surface will be used for the legend bounds.
Setting the BoundsMeasureType property will determine the unit of measurement to use for this rectangle.
Target Platforms: Windows 10, Windows 8.1, Windows 8, 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