class_docstr: Base class for NCF model benchmark.
code: def __init__(self, output_dir=None, default_flags=None, **kwargs):
      self.output_dir = output_dir
      self.default_flags = default_flags or {}
      # Run all benchmarks with ml_perf flag.
      self.default_flags["ml_perf"] = True
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  import time
  from absl import flags
  from absl.testing import flagsaver
  import tensorflow
  from utils import benchmark_wrappers
  from utils.recommendation import ncf_common
  from utils.recommendation import ncf_keras_main
  from utils.flags import core
label_desc: Use image node_id 1 to create a new NCFKerasBenchmarkBase object from inherited base classes: tf.test with example: obj = NCFKerasBenchmarkBase(output_dir, default_flags)