def METHOD_NAME():
    model = create_model(
        'Model',
        **{'123 invalid identifier!': (int, Field(123, alias='valid_identifier')), '!': (int, Field(0, alias='yeah'))},
    )
    assert _equals(str(signature(model)), '(*, valid_identifier: int = 123, yeah: int = 0) -> None')
    model = create_model('Model', **{'123 invalid identifier!': (int, 123), '!': (int, Field(0, alias='yeah'))})
    assert _equals(str(signature(model)), '(*, yeah: int = 0, **extra_data: Any) -> None')