code: def _import_parsers():
      
  
      global ARCGIS_NODES
      global ARCGIS_ROOTS
      global ArcGISParser
  
      global FGDC_ROOT
      global FgdcParser
  
      global ISO_ROOTS
      global IsoParser
  
      global VALID_ROOTS
  
      if ARCGIS_NODES is None or ARCGIS_ROOTS is None or ArcGISParser is None:
          from gis_metadata.arcgis_metadata_parser import ARCGIS_NODES
          from gis_metadata.arcgis_metadata_parser import ARCGIS_ROOTS
          from gis_metadata.arcgis_metadata_parser import ArcGISParser
  
      if FGDC_ROOT is None or FgdcParser is None:
          from gis_metadata.fgdc_metadata_parser import FGDC_ROOT
          from gis_metadata.fgdc_metadata_parser import FgdcParser
  
      if ISO_ROOTS is None or IsoParser is None:
          from gis_metadata.iso_metadata_parser import ISO_ROOTS
          from gis_metadata.iso_metadata_parser import IsoParser
  
      if VALID_ROOTS is None:
          VALID_ROOTS = {FGDC_ROOT}.union(ARCGIS_ROOTS + ISO_ROOTS)
docs: Lazy imports to prevent circular dependencies between this module and utils