code: def parent_link_extent(self):
          # type: () -> int
          '''
          Get the extent of the parent of this entry if it has one.
  
          Parameters:
           None.
          Returns:
           The logical block number of the parent if it exists.
          '''
          if not self._initialized:
              raise pycdlibexception.PyCdlibInternalError('Rock Ridge extension not yet initialized')
  
          if self.dr_entries.pl_record is not None:
              return self.dr_entries.pl_record.parent_log_block_num
          if self.ce_entries.pl_record is not None:
              return self.ce_entries.pl_record.parent_log_block_num
  
          raise pycdlibexception.PyCdlibInternalError('Asked for parent extent for non-existent parent record'f parent_link_extent(self):
          # type: () -> int
          '''
          Get the extent of the parent of this entry if it has one.
  
          Parameters:
           None.
          Returns:
           The logical block number of the parent if it exists.
          '''
          if not self._initialized:
              raise pycdlibexception.PyCdlibInternalError('Rock Ridge extension not yet initialized')
  
          if self.dr_entries.pl_record is not None:
              return self.dr_entries.pl_record.parent_log_block_num
          if self.ce_entries.pl_record is not None:
              return self.ce_entries.pl_record.parent_log_block_num
  
          raise pycdlibexception.PyCdlibInternalError('Asked for parent extent for non-existent parent record')
docs: Get the extent of the parent of this entry if it has one.
  
          Parameters:
           None.
          Returns:
           The logical block number of the parent if it exists.