code: function initLoadingState(btnEl) {
            if (cfg.btnLoadingClass && !cfg.addClassToCurrentBtnOnly) {
              btnEl.addClass(cfg.btnLoadingClass);
            }
            if (cfg.disableBtn && !cfg.disableCurrentBtnOnly) {
              btnEl.attr('disabled', 'disabled');
            }
          }
docs: Handles everything to be triggered when the button is set
  to loading state.
  @param {Object}btnEl