Extension methods for Map-like structures
Static methods
staticinlinewithKey<K, V>(map:IMap<K, V>, key:K):Option<V>
Attempts to find key in map, returning None if it's not found
staticwithKeyOrInsertNew<K, V>(map:IMap<K, V>, key:K, ifNotPresent:() ‑> V):V
Attempts fo find key in map, and inserts a generated value if it's not found