code: function create() {
      var args = Array.prototype.slice.call(arguments);
      var conf = {};
  
      args.forEach(function(config) {
          extend(conf, config);
      });
  
      if (conf.get === undefined) {
          bindGetMethod(conf);
      } else {
          throw new Error('`get` property cannot be the root key of config');
      }
  
      return conf;
  }
docs: create a config with multi objects.
  
  The latter object will overwrite the former recursively.
  
  @example
  create({a: 1, b: 2}, {a: 0, c: 3});  // => {a: 0, b: 2, c: 3}
  
  @param  {Object...} source  a set of config objects.
  @return {Object}  The final config object.
  @method create