def test_providing_before_op_explicitly(self):
        """
        When using mb.set_before_op, the builder will still respect the one provided by the user.
        """
        block = self.get_block()
        ops = list(block.operations)
        op1, op2 = ops[0], ops[1]
        with block:
            x = op1.x
            with mb.set_before_op(op1):
                x_1_5 = mb.relu(x=x, name="x1_5", before_op=op2)
        self.verify_op_name(block, ["x1", "x1_5", "x2"])

        When using mb.set_before_op, the builder will still respect the one provided by the user.
        
coremltools/converters/mil/mil/tests/test_programs.py