class OpRegGenImpl(transformer.CodeGenerator):
  """Visit the AST and generate C++ op registration functions."""

  def __init__(self, ctx):
    super(OpRegGenImpl, self).__init__(ctx)
    self.ctx = ctx

  def visit_Name(self, node):
    return node.id

  def visit_Constant(self, node):
    return node.value

  def visit_keyword(self, node):
    return node.arg, self.visit(node.value)

  def visit_List(self, node):