question: public CustomEntryConcurrentHashMap ( final Map < ? extends K , ? extends V > m ) { this ( Math . max ( ( int ) ( m . size ( ) / DEFAULT_LOAD_FACTOR ) + 1 , DEFAULT_INITIAL_CAPACITY ) , DEFAULT_LOAD_FACTOR , DEFAULT_CONCURRENCY_LEVEL , false ) ; putAll ( m ) ; }
target:  Creates a new map with the same mappings as the given map. The map is created with a capacity of 1.5 times the number of mappings in the given map or 16 (whichever is greater), and a default load factor (0.75) and concurrencyLevel (16).