code: def testRunMetadataEmpty(self):
      output_dir = test.get_temp_dir()
      run_metadata = config_pb2.RunMetadata()
      graph = test.mock.MagicMock()
      op1 = test.mock.MagicMock()
      op1.name = "Add/123"
      op1.traceback = [("a/b/file1", 10, "some_var")]
      op1.type = "add"
      graph.get_operations.return_value = [op1]
  
      profiles = pprof_profiler.get_profiles(graph, run_metadata)
      self.assertEqual(0, len(profiles))
      profile_files = pprof_profiler.profile(
          graph, run_metadata, output_dir
      )
      self.assertEqual(0, len(profile_files))
  
file_path: tensorflow/tensorflow/python/profiler/pprof_profiler_test.py
imports: import gzip
  from proto import profile_pb2
  from tensorflow.core.framework import step_stats_pb2
  from tensorflow.core.protobuf import config_pb2
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import while_loop
  from tensorflow.python.platform import test
  from tensorflow.python.profiler import pprof_profiler
label_desc: Use image node_id 2 for calling the PprofProfilerTest obj's underlying member method code with example usage: obj.testRunMetadataEmpty() without return types