Returns the distance between two nodes. The default implementation considers the shortest distance between the two nodes. If the nodes correspond to top-level Go objects, the width and height of the GoObject is factored into the distance between the nodes. If the nodes do not correspond to top-level Go objects, then the nodes implicitly have a width and height of zero, and the distance is calculated.

protected virtual double GetNodeDistance( 
   ForceDirectedVertex vertexA,
   ForceDirectedVertex vertexB
)