human
I wrote the below code

    if (isinstance(node.op, tensor.Elemwise) and (node.op.scalar_op == scalar_sigmoid)):
        out = ultra_fast_sigmoid(node.inputs[0])
        copy_stack_trace(node.outputs[0], out)
        def values_eq_approx_remove_low_prec(a, b):
            return tensor.TensorType.values_eq_approx(a, b, atol=0.02)
        out.tag.values_eq_approx = values_eq_approx_remove_low_prec
        return [out]

What's a good function header?
assistant
#Here's a good function header.

@gof.local_optimizer([sigmoid])
def local_ultra_fast_sigmoid(node):