def METHOD_NAME(self, basis):
    _class = self.getClass(basis)
    # expand should take an Image/Volume and return a NumPy array of type
    # basis.coefficient_dtype
    result = basis.expand(
        _class(np.zeros((basis.nres,) * basis.ndim, dtype=basis.dtype))
    )
    assert isinstance(result, np.ndarray)
    assert result.dtype == basis.coefficient_dtype