Query block loading icon can not show out, no contents in docs

hi, heroes, how can i show out the loading icon here? i tried couple of times, it just can not show out when loadding contents. i am not sure it’s a bug or i am setting in wrong way

what does it mean of “history”, “end”, “error”

plus, ican not find anything on this in offical docs

There is no need to write in FULL CAPS. It sounds rude.

, o , my god, i do not know about this, let me low the caps. thanks to tell me, @dranzer ,