public void addModel(NavigationModel other){
  for (  Group group : other.getGroups()) {
    addGroup(group);
  }
  for (  View view : other.getViews()) {
    addView(view);
  }
}

public void addModel ( NavigationModel other ) { for ( Group group : other . getGroups ( ) ) { addGroup ( group ) ; } for ( View view : other . getViews ( ) ) { addView ( view ) ; } }
add another navigationmodel to this one . this is done by adding all groups and view from the other model to this one .
