debug: add __prometheus dir

Author: nss10

gen3workflow/metrics.py

@@ -12,6 +12,7 @@ def __init__(self, prometheus_dir: str, enabled: bool = True) -> None:
         super().__init__(
             prometheus_dir=config["PROMETHEUS_MULTIPROC_DIR"], enabled=enabled
         )
+        self.__prometheus_dir = prometheus_dir
         logger.debug(f"Create a dummy metric for testing purposes: ")
         self.add_create_task_api_interaction(
             method="GET",
@@ -30,4 +31,6 @@ def add_create_task_api_interaction(
         self.increment_counter(name="gen3_workflow_tasks_created", labels=kwargs)
 
     def __str__(self):
-        return f"Metrics(enabled={self.enabled}, prometheus_dir={self.prometheus_dir})"
+        return (
+            f"Metrics(enabled={self.enabled}, prometheus_dir={self.__prometheus_dir})"
+        )