'_path_for_test_id returns a relative path of $module/$class/$method for
the given test id.'

@given(test_id=fqpns, max_length=integers(min_value=1, max_value=64))
def test_directory_for_test(self, test_id, max_length):

    assume((test_id.count('.') > 1))
    path = _path_for_test_id(test_id, max_length)
    self.expectThat(path, Not(StartsWith('/')))
    segments = path.split('/')
    self.expectThat(segments, HasLength(3))
    self.assertThat(segments, AllMatch(AfterPreprocessing(len, MatchesAny(LessThan(max_length), Equals(max_length)))))
