Number of top-level keys; 0 for an input that is not a key/value object.
Top-level key → UTF-8 byte length of its value's JSON form; -1 when the value cannot be serialized.
OptionalkeysTrue when keys lists only the MAX_TEMPLATE_DATA_SHAPE_KEYS largest values.
Sum of the UTF-8 JSON byte lengths of all top-level values (values that cannot be serialized count as 0). For an input that is not a key/value object: the UTF-8 byte length of its JSON form, or -1 when it cannot be serialized.
Shape of one template input: key names and sizes, never values. An input that is not a key/value object (a string, number, boolean, null or array) has no keys.