File closeflush in XML Adapter V42

How do I explicitly flush/close a “File Write” operation?

What I’m trying to do with the XML Adapter is:
Subscribe to Document->Create XML file->FTP PUT XML file

The XML file directory entry in UNIX is created (with a 0 byte length), but it’s contents are not available at the time of the FTP PUT. The contents are not available until after the Integration Component has completed.

I’ve executed an endTransaction with COMMIT and that didn’t write the file contents.