setFrom method
Set the values by copying them from other.
Implementation
void setFrom(Vector4 other) {
  final otherStorage = other._v4storage;
  _v4storage[3] = otherStorage[3];
  _v4storage[2] = otherStorage[2];
  _v4storage[1] = otherStorage[1];
  _v4storage[0] = otherStorage[0];
}