code: public boolean hasContactsWithinDistance(double distance) {
  
  		if (distance>=cutoff)
  			throw new IllegalArgumentException("Given distance "+
  					String.format("%.2f", distance)+" is larger than contacts' distance cutoff "+
  					String.format("%.2f", cutoff));
  
  		for (AtomContact contact:this.contacts.values()) {
  			if (contact.getDistance()<distance) {
  				return true;
  			}
  		}
  		return false;
  	}
docs: Returns true if at least 1 contact from this set is within the given distance.
  Note that if the distance given is larger than the distance cutoff used to
  calculate the contacts then nothing will be found.
  @param distance
  @return
  @throws IllegalArgumentException if given distance is larger than distance cutoff
  used for calculation of contacts