code: public void checkConstraints(String checkLevel) throws ConstraintException
      {
          // check constraints now after all classes have been processed
          for (Iterator it = getClasses(); it.hasNext();)
          {
              ((ClassDescriptorDef)it.next()).checkConstraints(checkLevel);
          }
          // additional model constraints that either deal with bigger parts of the model or
          // can only be checked after the individual classes have been checked (e.g. specific
          // attributes have been ensured)
          new ModelConstraints().check(this, checkLevel);
      }
docs: Checks constraints on this model.
  
  @param checkLevel The amount of checks to perform
  @throws ConstraintException If a constraint has been violated