anchor.diff:  class Float32x4 {
     @patch
     @pragma("vm:prefer-inline")
  -  factory Float32x4(double x, double y, double z, double w) =>
  -      _Float32x4FromDoubles(x, y, z, w);
  +  factory Float32x4(double x, double y, double z, double w) {
  +    _throwIfNull(x, 'x');
  +    _throwIfNull(y, 'y');
  +    _throwIfNull(z, 'z');
  +    _throwIfNull(w, 'w');
  +    return _Float32x4FromDoubles(x, y, z, w);
  +  }
   
     @pragma("vm:exact-result-type", _Float32x4)
     static _Float32x4 _Float32x4FromDoubles(
  
positive.code: class Int32x4 {
    @patch
    @pragma("vm:prefer-inline")
    factory Int32x4(int x, int y, int z, int w) => _Int32x4FromInts(x, y, z, w);
  
    @pragma("vm:exact-result-type", _Int32x4)
    static _Int32x4 _Int32x4FromInts(int x, int y, int z, int w)
  
negative.code:   @pragma("vm:exact-result-type", _Float32x4)
    Float32x4 shuffleMix(Float32x4 zw, int mask) native "Float32x4_shuffleMix";
  
    @pragma("vm:prefer-inline")
    Float32x4 withX(double x) {
      _throwIfNull(x, 'x');
      return _withX(x);
    }
  
    @pragma("vm:exact-result-type", _Float32x4)
    Float32x4 _withX(double x) native "Float32x4_setX";
  
    @pragma("vm:prefer-inline")
    Float32x4 withY(double y) {
      _throwIfNull(y, 'y');
      return _withY(y);
    }
  
    @pragma("vm:exact-result-type", _Float32x4)
    Float32x4 _withY(double y) native "Float32x4_setY";
  
    @pragma("vm:prefer-inline")
    Float32x4 withZ(double z) {
      _throwIfNull(z, 'z');
      return _withZ(z);
    }
  
    @pragma("vm:exact-result-type", _Float32x4)
    Float32x4 _withZ(double z) native "Float32x4_setZ";
  
    @pragma("vm:prefer-inline")
    Float32x4 withW(double w) {
      _throwIfNull(w, 'w');
      return _withW(w);
    }
  
    @pragma("vm:exact-result-type", _Float32x4)
    Float32x4 _withW(double w) native "Float32x4_setW";
  
    @pragma("vm:exact-result-type", _Float32x4)
    Float32x4 min(Float32x4 other) native "Float32x4_min";
    @pragma("vm:exact-result-type", _Float32x4)
  