Auto Collapse default
document.addEventListener("DOMContentLoaded", function(event) {
                            new MetisMenu('#menu1');
});
No Collapse
document.addEventListener("DOMContentLoaded", function(event) {
                            new MetisMenu('#menu2', {
                            toggle: false
  });
});
RTL SUPPORT RTL
document.addEventListener("DOMContentLoaded", function(event) {
                                new MetisMenu('#menu3');
});