code: public List<DomainObjectType> getDomainObjectTypes() {
  		List<DomainObjectType> resultList = new ArrayList<DomainObjectType>();
  		GrNode infoNode = loadDomainInfoNode();
  		GrProperty prop = infoNode.getProperty(DomainInfoLabel2ClassProperty);
  		if (prop != null) {
  			@SuppressWarnings("unchecked")
  			List<String> val = (List<String>) prop.getValue();
  			for (String str : val) {
  				String[] c2l = str.split("=");
  				resultList.add(new DomainObjectType(c2l[1], c2l[0]));
  			}
  		}
  		return resultList;
  	}
docs: answer a list of DomainObjectTypes stored in the domain graph
  @return a list of DomainObjectTypes