allow UniqueIdProcessor as key flag

src/ProcessorsTrait.php

@@ -38,7 +38,9 @@ trait ProcessorsTrait
      */
     protected function applyUidProcessor(array $processorFlags, $logger): void
     {
-        if (in_array(self::PROCESSOR_UNIQUE_ID, $processorFlags, true)) {
+        if (in_array(self::PROCESSOR_UNIQUE_ID, $processorFlags, true) ||
+            in_array(self::PROCESSOR_UNIQUE_ID, array_keys($processorFlags), true)
+        ) {
             $logger->pushProcessor(new UidProcessor());
         }
     }