record_controller_2.rb

class RecordsController < ApplicationController
    def update
        # TODO: remove the line below when the testing is complete
        sleep(1) if 0 == params[:input].length % 2
        @record = Record.find(params[:id])
        @record.update(field_name: params[:input]) if params[:version_number] > @record.version_number
    end
end