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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _create_forward(out_node):
 """Create a user-friendly forward function. Ensures that a single value instead of a tuple is returned if the user asked for the gradient with respect to only one input. Args: out_node: The function definition AST. Returns: The function definition with potentially changed return statement. """

  retval = out_node.body[0].body[-1]
  if len(retval.value.elts) == 1:
    retval.value = retval.value.elts[0]
  return out_node