code: function show(tree, prev, level) {
      level = level + 1;
  
      if (tree) {
        //FIXME: prototype check
        for (var i in tree.dependencies) {
          if (tree.dependencies.hasOwnProperty(i)) {
            id++;
            var nodeName = NODE_NAME_PREFIX + id;
            var child = i + '@' + tree.dependencies[i].version;
  
            outputStream.write(format(' "%s" -> "%s"%s', prev, nodeName, EOL));
            outputStream.write(format(' "%s"[label="%s",style="filled",fillcolor="%d 1 1"]%s', nodeName, child, level / 15, EOL));
  
            show(tree.dependencies[i], nodeName, level);
          }
  
        }
      }
    }
docs: recursive
  
  @param tree {Object}
  @param prev {String}
  @param level {Number}