def METHOD_NAME(self, basis):
    x = Image(randn(*basis.sz, seed=self.seed), dtype=basis.dtype)
    # Express in an FB basis
    v1 = basis.expand(x)
    # Convert real FB coef to complex coef,
    cv = basis.to_complex(v1)
    # then convert back to real coef representation.
    v2 = basis.to_real(cv)
    # The round trip should be equivalent up to machine precision
    assert np.allclose(v1, v2)