code: function setButter(message, error) {
    var butter = getButterBar();
    // Prevent flicker on butter update by hiding it first.
    butter.hide();
    if (error) {
      butter.removeClass('info').addClass('error').text(message);
    } else {
      butter.removeClass('error').addClass('info').text(message);
    }
    butter.show();
    $(document).scrollTop(0);
  }
docs: ******* Common functions ******** Sets the status butter, optionally indicating if it's an error message.