code: def write_bel_namespace(self, file: TextIO, use_names: bool = False) -> None:
          
          if not self.is_populated():
              self.populate()
  
          if use_names and not self.has_names:
              raise ValueError
  
          values = (
              self._get_namespace_name_to_encoding(desc='writing names')
              if use_names else
              self._get_namespace_identifier_to_encoding(desc='writing identifiers')
          )
  
          write_namespace(
              namespace_name=self._get_namespace_name(),
              namespace_keyword=self._get_namespace_keyword(),
              namespace_query_url=self.identifiers_url,
              values=values,
              file=file,
          )
docs: Write as a BEL namespace file.