def extend_type(self, type_name, instances):
    """Provide a list of additional instances of a type.

    If the type doesn't previously exist it will be defined.

    Args:
      type_name: string name of a type.
      instances: list of entity names to add to this type.
    """
    if type_name not in self._symtab:
      self._symtab[type_name] = symbol.SymbolTable()
    for entity_name in instances:
      self._symtab[type_name].insert(entity_name)
Provide a list of additional instances of a type.

    If the type doesn't previously exist it will be defined.

    Args:
      type_name: string name of a type.
      instances: list of entity names to add to this type.
    
language/nql/nql/__init__.py