parameters: (self, dy)
docstring: Args:
              dy (CTensor): the gradient tensor from upper operations
          Raises:
              AssertionError: no backward function for this operator
docstring_summary: Args:
              dy (CTensor): the gradient tensor from upper operations
          Raises:
              AssertionError: no backward function for this operator
docstring_tokens: Args : dy ( CTensor ) : the gradient tensor from upper operations Raises : AssertionError : no backward function for this operator
function: def backward(self, dy):
          """
          Args:
              dy (CTensor): the gradient tensor from upper operations
          Raises:
              AssertionError: no backward function for this operator
          """
          assert False, ('no gradient for backward function')
function_tokens: def backward ( self , dy ) : assert False , ( 'no gradient for backward function' )