add test case for dd_llmobs_disabled

tests/llmobs/test_llmobs_service.py

@@ -213,6 +213,25 @@ def test_llm_span(LLMObs, mock_llmobs_span_writer):
     )
 
 
+def test_llm_span_with_dd_llmobs_disabled(LLMObs, mock_llmobs_span_writer, monkeypatch):
+    monkeypatch.setenv("DD_LLMOBS_ENABLED", "0")
+    LLMObs.enable()
+
+    with LLMObs.llm(model_name="test_model", name="test_llm_call", model_provider="test_provider") as span:
+        assert span.name == "test_llm_call"
+        assert span.resource == "llm"
+        assert span.span_type == "llm"
+        assert span.get_tag(SPAN_KIND) == "llm"
+        assert span.get_tag(MODEL_NAME) == "test_model"
+        assert span.get_tag(MODEL_PROVIDER) == "test_provider"
+
+    mock_llmobs_span_writer.enqueue.assert_called_with(
+        _expected_llmobs_llm_span_event(span, "llm", model_name="test_model", model_provider="test_provider")
+    )
+    assert not llmobs_service.enabled
+
+
+
 def test_llm_span_agentless(AgentlessLLMObs, mock_llmobs_span_agentless_writer):
     with AgentlessLLMObs.llm(model_name="test_model", name="test_llm_call", model_provider="test_provider") as span:
         assert span.name == "test_llm_call"