class_docstr: Tests for StreamOutputBackpressurePolicy.
class_docstr_tok: ["Tests","for","StreamOutputBackpressurePolicy","."]
code: def tearDownClass(cls):
      data_context = ray.data.DataContext.get_current()
      for k in cls._configs.keys():
          data_context.remove_config(k)
      data_context.execution_options.preserve_order = False
      ray.shutdown()
  
imports: import functools
  import time
  import unittest
  from collections import defaultdict
  from contextlib import contextmanager
  from unittest.mock import MagicMock, patch
  import numpy
  import pytest
  import ray
  from ray.data._internal.execution.backpressure_policy import ENABLED_BACKPRESSURE_POLICIES_CONFIG_KEY, ConcurrencyCapBackpressurePolicy, StreamingOutputBackpressurePolicy
  from ray.data.tests.conftest import restore_data_context
  from ray.data.tests.conftest import CoreExecutionMetrics, assert_core_execution_metrics_equals, get_initial_core_execution_metrics_snapshot
  from ray.tests.conftest import shutdown_only
label_desc: Use image node_id 2 for calling the TestStreamOutputBackpressurePolicy obj's underlying member method code with example usage: obj.tearDownClass(cls) without return types