mutate
inline fun <K, V> MutableMap<K, V>.mutateValues(transform: (entry: Map.Entry<K, V>) -> V): MutableMap<K, V>
inline fun <K, V> MutableMap<K, V>.mutateValues(transform: (key: K, value: V) -> V): MutableMap<K, V>
Applies transform to each entry in the map, reusing the same structure to keep them.
The mutable equivalent to Map.mapValues.