public bool IsInComparison(GuitarViewModel g)
 {
     if (g != null)
     {
         if (Guitar1 != null && g.Guitar.Id == Guitar1.Guitar.Id)
         {
             return(true);
         }
         else if (Guitar2 != null && g.Guitar.Id == Guitar2.Guitar.Id)
         {
             return(true);
         }
     }
     return(false);
 }
 public GuitarComparisonViewModel(GuitarViewModel g1, GuitarViewModel g2)
 {
     Guitar1 = g1;
     Guitar2 = g2;
 }