Possible error in assert_equal and assert_allclose for MultiFields

In their current form, both methods assert_equal and assert_allclose only perform a one sided test for MultiFields. This leads to some unexpected behaviour when comparing two Fields which are only equal one some sub-domain. In particular the following test

import nifty8 as ift
d = ift.RGSpace(10)
d = ift.MultiDomain.make({'a' : d, 'b' : d})
f = ift.from_random(d)
fp = f.extract_by_keys(['a',])
ift.extra.assert_equal(fp, f)

will pass, but

ift.extra.assert_equal(f, fp)

produces an error, as only the keys of the first input are looped over. The same goes for assert_allclose.

This does not look like an intended behaviour to me. @mtr, @parras, am I missing something here?