swift dictionary extension

gistfile1.txt

extension Dictionary {
    
    static func union(dic: Dictionary, other: Dictionary?) -> Dictionary {
        var mutableCopy = dic
        mutableCopy.add(other: other)
        return mutableCopy
    }
    
    mutating func add(other: Dictionary?) -> Void {
        guard let other = other else { return }
        other.forEach { (key, value) in
            self.updateValue(value, forKey:key)
        }
    }
    
}