get-model-relations.php

public static function definedRelations(): array
{

      return collect((new \ReflectionClass(get_called_class()))->getMethods())
          ->filter(
              fn($method) => !empty($method->getReturnType()) &&
                  str_contains(
                      $method->getReturnType(), 
                      'Illuminate\Database\Eloquent\Relations'
                 )
          )
          ->pluck('name')
          ->all();
 }