[ios]how can i set emmiterlayer rendermode?

Hi i develop core animation for iOS 5 and I want to use CAEmmiterLayer. But I need to开发者_开发百科 set some properties like rendermode. I get error that it is unsupported for iOS. But iOS 5 should have support CAEmmiterLayer no?

CA_EXTERN NSString * const kCAEmitterLayerPoints
    __OSX_AVAILABLE_STARTING (__MAC_10_6, __IPHONE_NA);

I find that in library.

Line __OSX_AVAILABLE_STARTING (__MAC_10_6, __IPHONE_NA); means that its not applicable(NA) on any iOS and only available on macosx 10.6+