whereValue method
Allows us to find an entry based on value
Example:
people.whereValue((value) => value.isEven);
// {John: 20, Peter: 22}
const Map<String, int> people = {'John': 20, 'Mary': 21, 'Peter':20};
Implementation
Map<K, V> whereValue(bool Function(V value) f) =>
{...where((key, value) => f(value))};