' This method returns true if two specified selections overlap, including when the
' end of one selection serves as the beginning of the other.
Private Function DoSelectionsOverlap(ByVal selection1 As TextRange, ByVal selection2 As TextRange) As Boolean
    ' Is either end of selection2 contained by selection1?
    If selection1.Contains(selection2.Start) OrElse selection1.Contains(selection2.End) Then
        ' If so, the selections overlap.
        Return True
        ' If not, selection2 may still entirely contain selection1.
        ' Is either end of selection1 contained by seleciotn2?
    ElseIf selection2.Contains(selection1.Start) OrElse selection2.Contains(selection1.End) Then
        ' If so, the selections overlap.
        Return True
        ' If neither selection contains the begging or end of the other selection, 
        'the selections do not overlap.
    Else
        Return False
    End If
End Function