correction of various problems

src/event/AsyncEventDelegate.php

@@ -106,7 +106,7 @@ final class AsyncEventDelegate{
 		$nonConcurrentHandlers = [];
 		foreach($handlers as $registration){
 			if($registration instanceof RegisteredAsyncListener){
-				if($registration->canBeCallConcurrently()){
+				if($registration->canBeCalledConcurrently()){
 					$this->promises->add($registration->callAsync($this->event));
 				}else{
 					$nonConcurrentHandlers[] = $registration;

src/event/AsyncEventTrait.php

@@ -26,8 +26,6 @@ namespace pocketmine\event;
 use pocketmine\promise\Promise;
 
 trait AsyncEventTrait {
-	private AsyncEventDelegate $delegate;
-
 	/**
 	 * @phpstan-return Promise<null>
 	 */

src/event/HandlerList.php

@@ -142,11 +142,8 @@ class HandlerList{
 		}
 		foreach($asyncListenersByPriority as $priority => $asyncListeners){
 			usort($asyncListeners, static function(RegisteredAsyncListener $a, RegisteredAsyncListener $b) : int{
-				if($a->canBeCallConcurrently()){
-					return $b->canBeCallConcurrently() ? 0 : -1;
-				}else{
-					return $b->canBeCallConcurrently() ? -1 : 0;
-				}
+				// concurrent listeners are sorted to the end of the list
+				return $b->canBeCalledConcurrently() <=> $a->canBeCalledConcurrently();
 			});
 			$listenersByPriority[$priority] = array_merge($listenersByPriority[$priority] ?? [], $asyncListeners);
 		}

src/event/RegisteredAsyncListener.php

@@ -51,7 +51,7 @@ class RegisteredAsyncListener extends RegisteredListener{
 		parent::__construct($handler, $priority, $plugin, $handleCancelled, $timings);
 	}
 
-	public function canBeCallConcurrently() : bool{
+	public function canBeCalledConcurrently() : bool{
 		return !$this->noConcurrentCall;
 	}