You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: comments_controller.rb
    path of file: ./repos/errbit/app/controllers/api/v1
    
    the code of the file until where you have to start completion: module Api
  module V1
    class CommentsController < ApplicationController
      skip_before_action :verify_authenticity_token
      skip_before_action :authenticate_
    
      def index
        results = benchmark("[api/v1/comments_controller/index] query time") do
          Comment.where(err_id: params[:problem_id]).only(FIELDS).to_a
        end

        respond_to do |format|
          format.any(:html, :json) { render json: results }
          format.xml { render xml: results }
        end
      end