code: @Override
  	public int getMaxLength() {
  		int max = 0;
  		boolean found = false;
  		for (Constraint c : constraints) {
  			int cM = c.getMaxLength();
  			if (cM != -1) {
  				max += cM;
  				found = true;
  			}
  		}
  		return found ? max : -1;
  	}
docs: Returns the sum of all maximum lengths of the sub-constraints
  
  @return the sum of all maximum lengths of the sub-constraints