~ small fix

interpreter/NassiShneidermann.py

@@ -84,4 +84,9 @@ class NassiShneidermanDiagram:
     def load_from_file(self, filepath:str, itp_custom_tags: Optional[Dict[str, List[str]]]):
         itp = JavaInterpreter(filepath)
         itp.reset_tags(itp_custom_tags)
-        self.function_scopes = itp.load_instruction_scopes()
+        self.function_scopes = itp.load_instruction_scopes()
+        
+        if not self.function_scopes:
+            return True
+        else:
+            return False