code: public static void addGroupsToStructure(Structure s, Collection<Group> groups, int model, boolean clone) {
  		Chain chainGuess = null;
  		for(Group g : groups) {
  			chainGuess = addGroupToStructure(s, g, model, chainGuess, clone);
  		}
  	}
docs: Add a list of groups to a new structure. Chains will be automatically
  created in the new structure as needed.
  @param s structure to receive the group
  @param g group to add
  @param clone Indicates whether the input groups should be cloned before
  being added to the new chain