code: void processHeader(InputStream dataInput) throws IOException {
          int formatVersion = dataInput.read();
          if (formatVersion < 0) {
              throw new EOFException();
          }
          ensureCondition(formatVersion == SERIALIZER_VERSION, "Unsupported format version %d.", formatVersion);
      }
docs: Reads a single unsigned byte from the given InputStream and interprets it as a Serializer Format Version, after
  which it validates that it is supported.
  
  @param dataInput The InputStream to read from.
  @throws IOException If an IO Exception occurred.