public static function getAllRelationshipsForModel($modelClassName)
    {
        $modelClassName = self::getModelClass($modelClassName);

        if (!isset(self::$relationshipCache[$modelClassName])) {
            $schemas = self::getAllSchemas();
            $relationships = [];

            foreach ($schemas as $schema) {
                if (isset($schema->relationships[$modelClassName])) {
                    $relationships = array_merge($relationships, $schema->relationships[$modelClassName]);
                }
            }

            self::$relationshipCache[$modelClassName] = $relationships;
        }

        return self::$relationshipCache[$modelClassName];
    }