feat: use unknown instead of None

Author: feng-95

veadk/tracing/telemetry/attributes/extractors/llm_attributes_extractors.py

@@ -824,8 +824,7 @@ def llm_server_address(params: LLMAttributesParams) -> ExtractorResponse:
         ExtractorResponse: Response containing the server address or 'unknown'
     """
     return ExtractorResponse(
-        content=getattr(params.invocation_context.agent, "model_api_base", None)
-        or "unknown"
+        content=getattr(params.invocation_context.agent, "model_api_base", "unknown")
     )
 
 

veadk/tracing/telemetry/exporters/apmplus_exporter.py

@@ -301,9 +301,7 @@ def record_call_llm(
             invocation_context.run_config
             and invocation_context.run_config.streaming_mode != StreamingMode.NONE
         )
-        server_address = (
-            getattr(invocation_context.agent, "model_api_base", None) or "unknown"
-        )
+        server_address = getattr(invocation_context.agent, "model_api_base", "unknown")
         attributes = {
             "gen_ai_system": "volcengine",
             "gen_ai_response_model": llm_request.model,