description

# containsValue method Null safety

bool containsValue (

1. Object? value

)
override

Returns true if this map contains the given `value`.

Returns true if any of the values in the map are equal to `value` according to the `==` operator.

## Implementation

    bool containsValue(Object? value) {
      for (K key in keys) {
        if (this[key] == value) return true;
      }
      return false;
    }