code: def _ReadTableHeader(self, file_object, table_header_offset):
      
      data_type_map = self._GetDataTypeMap('keychain_table_header')
  
      table_header, _ = self._ReadStructureFromFileObject(
          file_object, table_header_offset, data_type_map)
  
      return table_header
docs: Reads the table header.
  
      Args:
        file_object (file): file-like object.
        table_header_offset (int): offset of the tables header relative to
            the start of the file.
  
      Returns:
        keychain_table_header: table header.
  
      Raises:
        ParseError: if the table header cannot be read.