def find_additional_properties(instance, schema):
properties = schema.get("<STR_LIT>", {})<EOL>patterns = "<STR_LIT:|>".join(schema.get("<STR_LIT>", {}))<EOL>for property in instance:<EOL><INDENT>if property not in properties:<EOL><INDENT>if patterns and re.search(patterns, property):<EOL><INDENT>continue<EOL><DEDENT>yield property<EOL><DEDENT><DEDENT>
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.