internal fun readInt(source: BufferedSource): Int {
      try {
        val result = source.readDecimalLong()
        val line = source.readUtf8LineStrict()
        if (result < 0L || result > Integer.MAX_VALUE || line.isNotEmpty()) {
          throw IOException("expected an int but was \"$result$line\"")
        }
        return result.toInt()
      } catch (e: NumberFormatException) {