XML Multi-Group Data reader (XMLMultiGroupDataReader)
Read a VTK XML multi-group data file and the serial VTK XML data files to which it points.
The XML Multi-Group Data reader reads the VTK XML multi-group data file format. XML multi-group data files are meta-files that point to a list of serial VTK XML files. When reading in parallel, this reader will distribute sub-blocks among processors. The expected file extensions are .vtm and .vtmg.