Example: ActiveSupport::JSON.backend = "JSONGem"

  All internal Rails JSON encoding is now handled by ActiveSupport::JSON.encode().  Use of #to_json is not recommended, as it may clash with other libraries that overwrite it.  However, you can recover Rails specific functionality
  if you really want to use #to_json.

    gem 'json'
    ActiveSupport::JSON.backend = "JSONGem"

    class ActiveRecord::Base
      alias to_json rails_to_json
    end