- Minor code cleaning

src/Repository.php

@@ -158,19 +158,14 @@ class Repository implements RepositoryInterface
             throw new \Exception("Your entity class `" . get_class($entity) . "` cannot match entity type of repository `{$this->entityClass}`");
         }
 
-        $primaryKeyDefinition = Ulmus::resolveEntity($this->entityClass)->getPrimaryKeyField();
-
-        if ( $primaryKeyDefinition !== null ) {
+        if ($primaryKeyDefinition = Ulmus::resolveEntity($this->entityClass)->getPrimaryKeyField()) {
             $pkField = key($primaryKeyDefinition);
 
             $this->eventExecute(Event\Query\Delete::class, $this, $entity);
 
             return $this->deleteFromPk($entity->$pkField);
         }
-        else {
-            $compoundKeyFields = Ulmus::resolveEntity($this->entityClass)->getCompoundKeyFields();
-
-            if ($compoundKeyFields) {
+        elseif ($compoundKeyFields = Ulmus::resolveEntity($this->entityClass)->getCompoundKeyFields()) {
             $this->eventExecute(Event\Query\Delete::class, $this, $entity);
 
             return $this->deleteFromCompoundKeys(array_combine($compoundKeyFields->column, array_map(fn($column) => $entity->$column, $compoundKeyFields->column)));
@@ -179,7 +174,6 @@ class Repository implements RepositoryInterface
             throw new \Exception(sprintf("No primary key found for entity %s", $this->entityClass));
         }
     }
-    }
 
     public function destroyAll(EntityCollection $collection) : void
     {