Map.drop

You're seeing just the function drop, go back to Map module for more information.

drop(map, keys)

drop(map(), [key()]) :: map()

Drops the given keys from map.

If keys contains keys that are not in map, they're simply ignored.

iex> Map.drop(%{a: 1, b: 2, c: 3}, [:b, :d])
%{a: 1, c: 3}