Write a method called flipMap() that takes in a map from string keys to string values, and returns a "reverse" or "inverse" version of the same map contents, mapping values from the first map to keys from the first map. For example, if the map provided has key "hello" mapped to value "world", then the map returned by your method should contain key "world" mapping to value "hello". You can modify the provided map, or create a new map.