code: @SuppressWarnings({ "rawtypes", "unchecked" })
  	public <T> T get(Class clazz, Object id) throws NoIdAnnotationFoundException, NoColumnAnnotationFoundException {
  		
  		//turn class to sql
  		SqlParamsPairs sqlAndParams = ModelSqlUtils.getGetFromObject(clazz, id);
  		
  		//query for list
  		List<T> list = this.list(sqlAndParams.getSql(), sqlAndParams.getParams(), clazz);
  		if (list.size() > 0) {
  			return list.get(0);
  		} else {
  			return null;
  		}
  	}
docs: 获取一个对象
  get object by id
  @param clazz
  @return
  @throws NoIdAnnotationFoundException
  @throws NoColumnAnnotationFoundException
  @throws NoDefinedGetterException