Check block param for null
Check block param for null

MilaFabio/vk-ios-sdk,VKCOM/vk-ios-sdk,Rusik/vk-ios-official-sdk,VKCOM/vk-ios-sdk,akaDuality/vk-ios-sdk,Sega-Zero/vk-ios-sdk,SanjoDeundiak/vk-ios-sdk