@@can.setKeyValue( key, value )

The @@can.setKeyValue symbol points to a Map-like object's property mutator function, which updates the value of the object's property with the supplied key. This is only applicable to objects where keyed properties are relevant (like maps).

var map = {
    set: function (key, value) {
        Observation.add(this, key);
        this[key] = value;
    }
}

map[canSymbol.for('can.setKeyValue')] = map.set;