putIfAbsent abstract method
Sets the absentValue
of key
if it's null
, and returns it.
If the key
value is already define and is NOT null
,
returns the previous value.
Implementation
FutureOr<V?> putIfAbsent(K key, V? absentValue);
Sets the absentValue
of key
if it's null
, and returns it.
If the key
value is already define and is NOT null
,
returns the previous value.
FutureOr<V?> putIfAbsent(K key, V? absentValue);