get abstract method
Returns the value associated with a given search key string.
For nested Maps, involving keys and sub-keys, returns the value associated with a given sub-key string. The sub-key is identified using a list, the first item of which is a top-level key and the last item the sub-key whose value is to be looked up and returned. See the nested Map example below.
The function requires a default value to return if no match to the given search key is found.
Implementation
V get(Object key, V defaultValue);