HH\AsyncGenerator::next
Return the Awaitable associated with the next key/value tuple in the
async generator, or null
public function next(): Awaitable<?(Tk, Tv)>;
You should always await the returned Awaitable to get the actual
key/value tuple.
If null is returned, that means you have reached the end of iteration.
You cannot call next() without having the value returned from a previous
call to next(), send(), raise(), having first awaited.
Returns
Awaitable<?(Tk,Tv)>- TheAwaitablethat produced the next key/value tuple in the generator. What is returned is a tuple ornull.