def METHOD_NAME(self) -> None:
    grammar = """
    start: sign thing other another $
    sign: ['-']
    thing: ['+']
    other: '*'
    another: '/'
    """
    self.assertEqual(self.calculate_first_sets(grammar), {
        "sign": {"", "'-'"},
        "thing": {"'+'", ""},
        "start": {"'+'", "'-'", "'*'"},
        "other": {"'*'"},
        "another": {"'/'"},
    })