title: d3 force graph: sticky nodes
body: <p>I would like to add a behavior to a force directed graph layout in D3 in such a way that once dropped, a dragged-and-dropped svg node sticks in its place, no longer changing position no matter what else happens in the graph. I have done some reading about this API but I can't figure out a way to get that one working.</p>
  
  <p>The problem I am trying to solve is allowing a user to "pick apart" a complex force graph.  </p>