Invokes the follower once with the initial value of
selector and again every time
store has a changed value of Selector. If follower is
async, each invocation will be awaited before the next is called.
The follower is passed the new value each time, and also a
control object which can be used to exit the loop like
return control.exit(myValue). If follower doesn't return an exit
instruction, its return value is ignored and it will be invoked again on the
the next Selector change.
Invokes the follower once with the initial value of selector and again every time store has a changed value of
Selector. If follower is async, each invocation will be awaited before the next is called.The
followeris passed the new value each time, and also a control object which can be used to exit the loop likereturn control.exit(myValue). Iffollowerdoesn't return an exit instruction, its return value is ignored and it will be invoked again on the the nextSelectorchange.