Start the editing of a point at the location given by _pt.
// C# public void MouseBegin( ITPoint _pt, WordBool _nearest );
' VisualBasic Public Sub MouseBegin( ByVal _pt As ITPoint, ByVal _nearest As WordBool )
// Oxygene public procedure MouseBegin( _pt : ITPoint; _nearest : WordBool );
If a point exists near _pt, then it will be moved /if movement occurs/, or otherwise deleted.
Editing must be started by EditShape.