code: def get_order_specification_visitor(name, registry=None):
      
      if registry is None:
          registry = get_current_registry()
      return registry.getUtility(IOrderSpecificationVisitor, name=name)
docs: Returns the class registered as the order specification
      visitor utility under the given name (one of the
      :const:`everest.querying.base.EXPRESSION_KINDS` constants).
  
      :returns: class implementing
          :class:`everest.interfaces.IOrderSpecificationVisitor`