How to collapse in the bootstrap nav from right side?

Question

Here is the following CSS code which I am adding in the stylesheet to collapse in the bootstrap nav form the right side of the webpage. But it's not working out. Please help me if someone know how to do it.

.collapsing{   
    position: relative !important;
    height: 0 !important;
    overflow: hidden !important;
    -webkit-transition: width .35s ease !important;
    -o-transition: width .35s ease !important;
    transition: width .35s ease !important;
}

.collapse{
    width:0 !important;
    position: absolute !important;
    right:0 !important;
    display: block;
}

.collapse.in{
    height:initial !important;
    width:100% !important;
    overflow: hidden !important;

}