code: def setUp(self):
      super().setUp()
      self.num_boxes = 5000
      os.environ["TF_TRT_ALLOW_NMS_TOPK_OVERRIDE"] = "1"
  
imports: import os
  from tensorflow.python.compiler.tensorrt import utils
  from tensorflow.python.compiler.tensorrt.test import tf_trt_integration_test_base
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import image_ops_impl
  from tensorflow.python.platform import test
label_desc: Use image node_id 1 for calling the CombinedNmsTopKOverride obj's underlying member method code with example usage: obj.setUp() without return types