code: def list_tables(self):
          '''
          Load existing tables and their descriptions.
  
          :return:
          '''
          if not self._tables:
              for table_name in os.listdir(self.db_path):
                  self._tables[table_name] = self._load_table(table_name)
  
          return self._tables.keys(f list_tables(self):
          '''
          Load existing tables and their descriptions.
  
          :return:
          '''
          if not self._tables:
              for table_name in os.listdir(self.db_path):
                  self._tables[table_name] = self._load_table(table_name)
  
          return self._tables.keys()
docs: Load existing tables and their descriptions.
  
          :return: