docs: public static boolean sameZero(Object x, Object y) {
          if (!typeof(x).equals(typeof(y))) {
              return false;
          }
          if (x instanceof Number) {
              if (isNaN(x) && isNaN(y)) {
                  return true;
              }
              final double dx = ((Number)x).doubleValue();
              if (y instanceof Number) {
                  final double dy = ((Number)y).doubleValue();
                  if (((dx == negativeZero) && (dy == 0.0)) ||
                      ((dx == 0.0) && dy == negativeZero)) {
                          return true;
                  }
              }
              return eqNumber(dx, y);
          }
          return eq(x, y);
      }