anchor.diff:    JSNumber operator %(@nullCheck num other) {
       // Euclidean Modulo.
       JSNumber result = JS<JSNumber>('!', r'# % #', this, other);
  -    if (result == 0) return (0 as JSNumber); // Make sure we don't return -0.0.
  +    if (result == 0) {
  +      return JS<JSNumber>('!', '0'); // Make sure we don't return -0.0.
  +    }
       if (result > 0) return result;
       if (JS<JSNumber>('!', '#', other) < 0) {
         return JS<JSNumber>('!', '# - #', result, other);
  
positive.code: 
  part of dart._interceptors;
  
  /**
   * The implementation of Dart's int & double methods.
   * These are made available as extension methods on `Number` in JS.
   */
  @JsPeerInterface(name: 'Number')
  class JSNumber extends Interceptor implements int, double {
    const JSNumber();
  
negative.code:   // Returns 1/this % m, with m > 0.
    @notNull
    int modInverse(@nullCheck int m) {
      if (this is! int) throwArgumentErrorValue(this);
      if (m <= 0) throw RangeError.range(m, 1, null, "modulus");
      if (m == 1) return 0;
      int t = this;
  