extended

# File activerecord/lib/active_record/explain.rb, line 5
    def self.extended(base)
      base.class_eval do
        # If a query takes longer than these many seconds we log its query plan
        # automatically. nil disables this feature.
        class_attribute :auto_explain_threshold_in_seconds, :instance_writer => false
        self.auto_explain_threshold_in_seconds = nil
      end
    end