def flashback(error_message, exception = nil)
      airbrake_class.send(:notify, exception) if airbrake_class
      flash[:error] = error_message
      begin
        redirect_to :back
      rescue ActionController::RedirectBackError
        redirect_to error_path
      end
    end
def flashback(error_message, exception = nil)
      airbrake_class.send(:notify, exception) if airbrake_class
      flash[:error] = error_message
      begin
        redirect_to :back
      rescue ActionController::RedirectBackError
        redirect_to error_path
      end
    end
Set the error flash and attempt to redirect back. If RedirectBackError is raised,
 redirect to error_path instead.