def load(self, requirements_file=None):
        """Load or reload requirements from a requirements.txt file.

        :param requirements_file: if not given, the filename used from
            initialization will be read again.
        """
        if requirements_file is None:
            requirements_file = self.filename
            if requirements_file is None:
                raise ValueError("no filename provided")
        elif isinstance(requirements_file, text_type):
            requirements_file = Path(requirements_file)
        self.clear()
        with requirements_file.open() as f:
            self.loads(f.read())

        if isinstance(requirements_file, (text_type, Path)):
            self.filename = requirements_file
def test_when_verbose_and_retcode_is_nonzero_output_should_be_had():
    expected_stderr = "this is something fnord"
    with patch.dict(
        pdbedit.__salt__,
        {
            "cmd.run_all": MagicMock(
                return_value={"stdout": "", "stderr": expected_stderr, "retcode": 1}
            )
        },
    ), patch("salt.modules.pdbedit.log.error", autospec=True) as fake_error_log:
        pdbedit.list_users(verbose=True)
        actual_error = fake_error_log.mock_calls[0].args[0]
        assert actual_error == expected_stderr