XML Hierarchical Data reader (XMLHierarchicalDataReader)
Read a VTK XML Hierarchical data file and the serial VTK XML files to which it points.
The XML Hierarchical Data reader reads the VTK XML hierarchical data file format. XML hierarchical data files are meta-files that point to a list of serial VTK XML files. When reading in parallel, it will distribute sub-blocks among processors. The expected file extensions are .vtm and .vthd.