         return props
 
 
-    ###
-    properties to cache, private.
-    ###
-    @_propOfCreatedAt: undefined 
-    @_propOfUpdatedAt: undefined
-    @_modelProps: undefined
-
-
-
     ###*
     get prop name whose type is CREATED_AT
     notice: only one prop should be enrolled to CREATED_AT

    @static
    @return {String} propName
    ###
    @getPropOfCreatedAt: ->

        if @_propOfCreatedAt is undefined

    @static
    @return {String} propName
    ###
    @_propOfUpdatedAt: undefined
    @getPropOfUpdatedAt: ->

        if @_propOfUpdatedAt is undefined
