add method
Adds value
to the set.
Returns true
if value
(or an equal value) was not yet in the set.
Otherwise returns false
and the required removal counter is incremented.
If a value equal to value
was already in the set, it is replaced with
value
.
Implementation
@override
bool add(E value) {
_counts[value] = (_counts[value] ?? 0) + 1;
return _inner.add(value);
}