Merge that only adds unique values about gabs HOT 3 CLOSED

func colisionFunction(source, dest interface{}) interface{} {
	destArr, destIsArray := dest.([]interface{})
	sourceArr, sourceIsArray := source.([]interface{})
	if destIsArray {
		if sourceIsArray {
			for _, sourceElement := range sourceArr {
				exists := false
				for _, destElement := range destArr {
					if sourceElement == destElement {
						exists = true
						break
					}
				}
				if !exists {
					destArr = append(destArr, sourceElement)
				}
			}
			return destArr
		}
		exists := false
		for _, destElement := range destArr {
			if source == destElement {
				exists = true
				break
			}
		}
		if exists {
			return destArr
		}
		return append(destArr, source)
	}

	if sourceIsArray {
		exists := false
		for _, sourceElement := range sourceArr {
			if dest == sourceElement {
				exists = true
				break
			}
		}
		if exists {
			return sourceArr
		}
		return append(sourceArr, dest)
	}

	if dest == source {
		return dest
	}
	return []interface{}{dest, source}
}