code: public boolean guidMatches(Rule other) {
  		if (other == null) {
  			throw new IllegalArgumentException("other must be non-null");
  		}
  
  		boolean matches = true;
  
  		matches &= (guid != null) ? guid.equals(other.getGuid()) : true;
  
  		return matches;
  	}
docs: /* checks whether other rule has same guid, i.e. is the same rule