code: function(tree, maxLevel) {
      this.each(tree, function(elem, i) {
        if (i == maxLevel && elem.children) {
          delete elem.children;
          elem.children = [];
        }
      });
    }
docs: /*
  Method: prune
  
  Clears all tree nodes having depth greater than maxLevel.
  
  Parameters:
  
  tree - (object) A JSON tree object. For more information please see <Loader.loadJSON>.
  maxLevel - (number) An integer specifying the maximum level allowed for this tree. All nodes having depth greater than max level will be deleted.