code: private int readInt(InputStream in, CRC32 crc) throws IOException {
          int s = readShort(in, crc);
          return ((readShort(in, crc) << 16) & 0xffff0000) | s;
      }
docs: Read an int.
  
  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 int read.
  
  @throws IOException