How to add dynamic slides in Virtual Swiper slides?

I have made swiper slides with the help of idangero’s swiper virtual slide. Pushed all slide and showing and swiping it correctly. Now I want to add some additional dynamic slides when the user reaches the last slide of the rendered slide, and for this, I am using mySwiper.virtual.appendSlide(slide);. Already prepared all the slides, in array form, and when the user slides the last slide then I m appendSlide method. It makes blank previous 4 slides and appending only one slide!!!