code: function(target) {
          target = OpenLayers.Util.applyDefaults(target, this.defaults);
          target.nodeTolerance = target.nodeTolerance || target.tolerance;
          target.vertexTolerance = target.vertexTolerance || target.tolerance;
          target.edgeTolerance = target.edgeTolerance || target.tolerance;
          this.targets.push(target);
      }
docs: Method: addTarget
  Add a configured target layer.
  
  Parameters:
  target - {Object} A target config.