code: function(visible) {
              var e = document.getElementById('imc_loading');
  
              if (typeof visible == 'undefined') {
                  return e.classList.contains('loading');
              }
  
              if (visible) {
                  e.classList.add('loading');
              }
              else {
                  e.classList.remove('loading');
              }
  
              return visible;
          }
docs: Toggle loading spinning indicator