code: public List<AtomContact> getContactsWithinDistance(double distance) {
  
  		List<AtomContact> list = new ArrayList<AtomContact>();
  		for (AtomContact contact:this.atomContacts) {
  			if (contact.getDistance()<distance) {
  				list.add(contact);
  			}
  		}
  		return list;
  	}
docs: Returns the list of atom contacts in this GroupContact that are within the given distance.
  @param distance
  @return