docs: public static double toInteger(double d) {
          // if it's NaN
          if (d != d)
              return +0.0;
  
          if (d == 0.0 ||
              d == Double.POSITIVE_INFINITY ||
              d == Double.NEGATIVE_INFINITY)
              return d;
  
          if (d > 0.0)
              return Math.floor(d);
  
          return Math.ceil(d);
      }