[Easy] Add str repr for IterationStats (#26232)

Signed-off-by: 22quinn <33176974+22quinn@users.noreply.github.com>

tests/v1/metrics/test_stats.py

@@ -0,0 +1,21 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+from vllm.v1.metrics.stats import IterationStats
+
+
+def test_iteration_stats_repr():
+    iteration_stats = IterationStats()
+    iteration_stats.iteration_timestamp = 0
+    expected_repr = ("IterationStats("
+                     "iteration_timestamp=0, "
+                     "num_generation_tokens=0, "
+                     "num_prompt_tokens=0, "
+                     "num_preempted_reqs=0, "
+                     "finished_requests=[], "
+                     "max_num_generation_tokens_iter=[], "
+                     "n_params_iter=[], "
+                     "time_to_first_tokens_iter=[], "
+                     "inter_token_latencies_iter=[], "
+                     "waiting_lora_adapters={}, "
+                     "running_lora_adapters={})")
+    assert repr(iteration_stats) == expected_repr