code: function $merge(params, fn) {
      if (
          Array.isArray(params) &&
          params.length === 2 &&
          params.every(p => typeof p === 'object')
      ) {
          return fn.merge(params[0], params[1]);
      }
      throw new Error('$merge expects an array of two objects');
  }
docs: Return the merge of two objects
  
  @param {[any, any]} params
  @returns {any}