feat: add optional param for passing an unique_id to call method.

ocpp/charge_point.py

@@ -237,7 +237,7 @@ async def _handle_call(self, msg):
             # when no '_on_after' hook is installed.
             pass
 
-    async def call(self, payload, suppress=True):
+    async def call(self, payload, suppress=True, unique_id=None):
         """
         Send Call message to client and return payload of response.
 
@@ -261,8 +261,12 @@ async def call(self, payload, suppress=True):
         """
         camel_case_payload = snake_to_camel_case(asdict(payload))
 
+        unique_id = (
+            unique_id if unique_id is not None else str(self._unique_id_generator())
+        )
+
         call = Call(
-            unique_id=str(self._unique_id_generator()),
+            unique_id=unique_id,
             action=payload.__class__.__name__[:-7],
             payload=remove_nones(camel_case_payload),
         )