docs: protected void payloadWritten(int payloadSize)
      {
          if (tc.isEntryEnabled())
              Tr.entry(tc, "payloadWritten", new Object[] { this, new Integer(payloadSize) });
  
          // Track the unwritten payload decrease directly. We take no account for this classes header
          // values in this figure. The total payload remains unchanged since we are not removing the
          // corresponding payload, just writing it to the underlying recovery log.
          _unwrittenDataSize -= payloadSize;
  
          // When writing existing payload, if the resulting unwritten data size has gone back down to 
          // zero then there will be no further need to account for the unwritten data header.
          // When we pass on this payload adjustment we must account for the header size.
          if (_unwrittenDataSize == 0)
          {
              _recLog.payloadWritten(payloadSize + _totalHeaderSize);
          }
          else
          {
              _recLog.payloadWritten(payloadSize);
          }
  
          if (tc.isDebugEnabled())
              Tr.debug(tc, "unwrittenDataSize = " + _unwrittenDataSize + " totalDataSize = " + _totalDataSize);
          if (tc.isEntryEnabled())
              Tr.exit(tc, "payloadWritten");
      }