Like t.same assert on array of objects, where element order doesn't matter.
A map is a collection of key-value pairs, with unique keys.
Entries is a list of key-value pairs, with unique keys.
A set is a collection of unique values.
An object is a collection of properties, with associated values.
Lists all possible subsets.
Lists is a pair of key list and value list, with unique keys.
subsets of Set