Plot model geometry created using COMSOL with MATLAB in every iteration

I am trying to simulate a model using MATLAB COMSOL interface. MATLAB 2016a and COMSOL 5.0.. I am varying few boundary of the model and tring to plot the geometry in each loop. I tried to use mphgeom() function to plot the geometry in every loop. With each loop, only the last boundary is plotted. Can someone suggest how to plot the boundaries in each iteration keeping the old one intact? A similar thing happens with "hold on" function in MATLAB but this function doesn't work for mphgeom().