creates a new map clone to m.

Returns all the keys that are in m2 that are not present in m1.

Checks if key exists in map m.

Intersect returns m1 values that keys are contained in m2.

Returns all keys present in both maps.

Keys returns keys of the map.

Returns a map with all keys that don't exist in both maps.

Returns a map that is m1 + m2 where in case of same keys, values from m1 are preferred.

Values returns values of the map.