'Put a test into a bucket according to its set of fixtures and the
value of its exempt_from_fixture_bundling attr.'

def add(self, test):

    if is_subclass_at_all(test.context, FastFixtureTestCase):
        key = (frozenset(getattr(test.context, 'fixtures', [])), getattr(test.context, 'exempt_from_fixture_bundling', False))
        self.buckets.setdefault(key, []).append(test)
    else:
        self.remainder.append(test)
