fix: solving issue with fm metrics operation

flamapy/metamodels/fm_metamodel/operations/fm_metrics.py

@@ -70,6 +70,7 @@ def calculate_metamodel_metrics(self, model: VariabilityModel) -> list[dict[str,
             if callable(getattr(self, method_name))
             and hasattr(getattr(self, method_name), "_is_metric_method")
         ]
+
         if self.filter is not None:
             metric_methods = [
                 method for method in metric_methods if method.__name__ in self.filter