text: from rpython.rlib import jit
  
  class Arity(object):
      _immutable_fields_ = ['arity_list[*]', 'at_least']
  
      def __init__(self, arity_list, at_least):
          self.arity_list = arity_list
          self.at_least = at_least
  
      @jit.elidable
      def list_includes(self, arity):
          return arity in self.arity_list
  
  Arity.unknown = Arity([], 0)
  