code: function(reposition) {
      if (reposition) {
        this.reposition();
        this.graph.eachNode(function(node) {
          node.startPos.rho = node.pos.rho = node.endPos.rho;
          node.startPos.theta = node.pos.theta = node.endPos.theta;
        });
      } else {
        this.compute();
      }
      this.plot();
    }
docs: /*
  Method: refresh
  
  Computes positions and plots the tree.
  
  Parameters:
  
  reposition - (optional|boolean) Set this to *true* to force all positions (current, start, end) to match.