code: public void writeExternal(java.io.ObjectOutput objectOutput)
                      throws java.io.IOException
      {
          if (Tracing.isAnyTracingEnabled() && trace.isEntryEnabled())
              trace.entry(this, cclass
                          , "writeExternal"
                          , "objectOutput=" + objectOutput + "(java.io.ObjectOutput)"
                              );
          objectOutput.writeByte(externalVersion);
          objectOutput.writeInt(objectStoreIdentifier);
          objectOutput.writeLong(storedObjectIdentifier);
  
          if (Tracing.isAnyTracingEnabled() && trace.isEntryEnabled())
              trace.exit(this, cclass
                         , "writeExternal"
                              );
      }
docs: /*
  (non-Javadoc)
  
  @see java.util.io.Externalizable.writeExternal(java.io.ObjectOutput)