def METHOD_NAME(instance, schema):
    """
    Return the set of additional properties for the given ``instance``.
    Weeds out properties that should have been validated by ``properties`` and
    / or ``patternProperties``.
    Assumes ``instance`` is dict-like already.
    """
    properties = schema.get("properties", {})
    patterns = "|".join(schema.get("patternProperties", {}))
    for property in instance:
        if property not in properties:
            if patterns and re.search(patterns, property):
                continue
            yield property