A reference to a ToolWindowGroup representing the ToolWindow's container when it is grouped with other ToolWindows. The ParentGroup property of a ToolWindow will never be a null reference (Nothing in Visual Basic).
Remarks
ToolWindows are considered to be grouped when their associated tabs are displayed.
It is required to always access a ToolWindowGroup via the ToolWindow.ParentGroup property and never cache this property value.
Requirements
Target Platforms: 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