code: int parseIntAt(final int fromIndex, final int length) {
          assert length >= 0;
          assert 0 <= fromIndex && (fromIndex + length) <= byteArray.length;
          final int multiplyMax = Integer.MAX_VALUE / RADIX;
          int result = 0;
          for (int i = 0; i < length; ++i) {
              if (result > multiplyMax) {
                  throwNumberIsToLargeException(fromIndex);
              }
              result *= RADIX;
              final int digit = byteToDigit(fromIndex + i);
              if (result > Integer.MAX_VALUE - digit) {
                  throwNumberIsToLargeException(fromIndex);
              }
              result += digit;
          }
          return result;
      }
docs: Parses characters in the specified part of the byte buffer into an integer
  This is a simplified version of {@link Integer#parseInt(String)}. It
  operates directly on the byte data and works only for positive numbers and
  a radix of 10.
  
  @param fromIndex position fo the byte range to convert into an integer
  @param length number of bytes to include in the range
  @return the integer value represented by the characters at the given
  range in the buffer.
  @throws NumberFormatException if a non-digit character was encountered or
  an overflow occurred.