updateValue method

V updateValue(
  1. K key,
  2. V update(
    1. V
    ),
  3. {V ifAbsent(
      )?}
    )

    Implementation

    V updateValue(K key, V Function(V) update, {V Function()? ifAbsent}) =>
        _safeMap.update(key, update, ifAbsent: ifAbsent);