code: def test_base_output_handler_setup_output_metrics():
      engine = Engine(lambda engine, batch: None)
      true_metrics = {"a": 0, "b": 1}
      engine.state = State(metrics=true_metrics)
      engine.state.output = 12345
  
      # Only metric_names
      handler = DummyOutputHandler(
          "tag", metric_names=["a", "b"], output_transform=None
      )
      metrics = handler._setup_output_metrics_state_attrs(
          engine=engine, key_tuple=False
      )
      assert metrics == {"tag/a": 0, "tag/b": 1}
  
      # Only metric_names with a warning
      handler = DummyOutputHandler(
          "tag", metric_names=["a", "c"], output_transform=None
      )
      with pytest.warns(UserWarning):
          metrics = handler._setup_output_metrics_state_attrs(
              engine=engine, key_tuple=False
          )
      assert metrics == {"tag/a": 0}
  
      # Only output as "output"
      handler = DummyOutputHandler(
          "tag", metric_names=None, output_transform=lambda x: x
      )
      metrics = handler._setup_output_metrics_state_attrs(
          engine=engine, key_tuple=False
      )
      assert metrics == {"tag/output": engine.state.output}
  
      # Only output as "loss"
      handler = DummyOutputHandler(
          "tag",
          metric_names=None,
          output_transform=lambda x: {"loss": x},
      )
      metrics = handler._setup_output_metrics_state_attrs(
          engine=engine, key_tuple=False
      )
      assert metrics == {"tag/loss": engine.state.output}
  
      # Metrics and output
      handler = DummyOutputHandler(
          "tag",
          metric_names=["a", "b"],
          output_transform=lambda x: {"loss": x},
      )
      metrics = handler._setup_output_metrics_state_attrs(
          engine=engine, key_tuple=False
      )
      assert metrics == {
          "tag/a": 0,
          "tag/b": 1,
          "tag/loss": engine.state.output,
      }
  
      # All metrics
      handler = DummyOutputHandler(
          "tag", metric_names="all", output_transform=None
      )
      metrics = handler._setup_output_metrics_state_attrs(
          engine=engine, key_tuple=False
      )
      assert metrics == {"tag/a": 0, "tag/b": 1}
  
imports: from typing import Any, Union
  from unittest.mock import call, MagicMock
  import pytest
  import torch
  from ignite.contrib.handlers.base_logger import BaseLogger, BaseOptimizerParamsHandler, BaseOutputHandler, BaseWeightsHandler, BaseWeightsScalarHandler
  from ignite.engine import Engine, Events, EventsList, State
  from tests.ignite.contrib.handlers import MockFP16DeepSpeedZeroOptimizer
label_desc: Use image node_id 2 for calling a global function with example usage: test_base_output_handler_setup_output_metrics() without return types