add method
Implementation
void add(Vector4 arg) {
final Float32List argStorage = arg._v4storage;
_v4storage[0] = _v4storage[0] + argStorage[0];
_v4storage[1] = _v4storage[1] + argStorage[1];
_v4storage[2] = _v4storage[2] + argStorage[2];
_v4storage[3] = _v4storage[3] + argStorage[3];
}