def EnterSignature(self, node):
    super(MergeTypeParameters, self).EnterSignature(node)
    assert (self.type_param_union is None)
    self.type_param_union = collections.defaultdict(list)
def EnterSignature(self, node):
    super(MergeTypeParameters, self).EnterSignature(node)
    assert (self.type_param_union is None)
    self.type_param_union = collections.defaultdict(list)