docs: def load_directory(self, directory, **kwargs):
          """ loads all rdf files in a directory
  
          args:
              directory: full path to the directory
          """
          log.setLevel(kwargs.get("log_level", self.log_level))
          conn = self.__get_conn__(**kwargs)
          file_extensions = kwargs.get('file_extensions', conn.rdf_formats)
          file_list = list_files(directory,
                                 file_extensions,
                                 kwargs.get('include_subfolders', False),
                                 include_root=True)
          for file in file_list:
              self.load_file(file[1], **kwargs)
          log.setLevel(self.log_level)