AwaitGroup

Interface:

 /**
  * @param int $count
  * @return void
  *
  * This function is used to add the count to the group
  */
 public function add(int $count): void;

 /**
  * @return Generator
  *
  * This function is used to decrement the count
  */
 public function done(): Generator;

 /**
  * @return bool
  *
  * This function is used to check if the count is zero
  */
 public function isDone(): bool;

 /**
  * @return int
  *
  * This function is used to get the count
  */
 public function getCount(): int;

 /**
  * @return void
  *
  * This function is used to wait for the count to be zero
  */
 public function reset(): void;