How to set default text in TextPanel?

I have been following this...

https://intellij-support.jetbrains.com/hc/en-us/community/posts/206777955-Accessing-XML-through-IDEA-DOM-and-UI-problems?page=1#community_comment_206719609

along with

http://www.jetbrains.org/intellij/sdk/docs/reference_guide/frameworks_and_external_apis/xml_dom_api.html

and I want to populate a TextPanel with the tag/attribute I'm binding it to, but I can't figure out how to do that.  I'm using doBind to bind a TextControl to a TextPanel, but the panel is not prepopulating with the xml.  However if I then type something into the TextPanel it's reflected in the xml (so I know the binding is happening).  Or rather the binding is only one way, from the Form to the XML.  I want it to be bidirectional or at least the ability to populate the Form on load of the XML file.