def it_creates_a_new_child_if_one_is_not_present(self, parent_elm):
child_elm = get_or_add(parent_elm, 'p:baz')
assert child_elm.tag == qn('p:baz')
assert child_elm.getparent() is parent_elm
def it_returns_a_matching_child_if_present(
self, parent_elm, known_child_nsptag_str, known_child_elm):
child_elm = get_or_add(parent_elm, known_child_nsptag_str)
assert child_elm is known_child_elm
