code: private int readShort(InputStream in, CRC32 crc) throws IOException {
          int b = readByte(in, crc);
          return ((readByte(in, crc) << 8) & 0x00ff00) | b;
      }
docs: Read a short.
  
  We do not expect to get a -1 reading.  If we do, we throw exception.
  Update the crc as we go.
  
  @param in InputStream to read.
  @param crc CRC to update.
  @return Short read.
  
  @throws IOException