Public Function BuildMultiProjectSummaryGraph( _
   Optional ByVal XAxisField As String = "", _
   Optional ByVal GroupByField As String = "", _
   Optional ByVal SumOfField As String = "", _
   Optional ByVal SelectedProjects As String = "", _
   Optional ByVal MaxCols As Long = 0, _
   Optional ByVal Filter As Variant, _
   Optional ByVal ForceRefresh As Boolean = False, _
   Optional ByVal ShowFullPath As Boolean = False, _
   Optional ByVal ShowNullParents As Boolean = False _
) As Object