def test_pipe_should_return_an_empty_string(self) -> None:

    def echo(x: str) -> str:
        return f'echo {x}'
    param = 'hello world'
    output = pipe(echo)(param)
    self.assertEqual(output, f'echo {param}')
def test_pipe_should_return_an_empty_string(self) -> None:

    def echo(x: str) -> str:
        return f'echo {x}'
    param = 'hello world'
    output = pipe(echo)(param)
    self.assertEqual(output, f'echo {param}')