title: GoJS get parent Node from TextBlock click handler
body: <p>Is there a way to get to the parent <code>Node</code> or the parent <code>GraphObject</code>'s in general in GoJS? I'm inside a <code>TextBlock</code> and need access to the model data in the click handler. <code>Panel.findObject(id)</code> only works from top to botton in the object hierarchy and a <code>TextBlock</code> has no access to that method either way.
  I tried <code>diagram.findNodeForKey</code>, if I get access to the key from the child element, but same problem here. I thought there has to be a simple way to get to the parent `Node/Part somehow, but I didn't find any suitable function for that in the API.</p>
  
  <p>As a workaround I use <code>diagram.selection.first().data</code> at the moment to get to the Node and the bound model data, it works in my case, but seems a little dirty.</p>