docstr: Tests 2 images inserted/accessed in EventAccumulator.
code: def testImages(self):
      """Tests 2 images inserted/accessed in EventAccumulator."""
      gen = _EventGenerator(self)
      acc = ea.EventAccumulator(gen)
      im1 = ea.ImageEvent(
          wall_time=1,
          step=10,
          encoded_image_string=b"big",
          width=400,
          height=300,
      )
      im2 = ea.ImageEvent(
          wall_time=2,
          step=12,
          encoded_image_string=b"small",
          width=40,
          height=30,
      )
      gen.AddImage(
          "im1",
          wall_time=1,
          step=10,
          encoded_image_string=b"big",
          width=400,
          height=300,
      )
      gen.AddImage(
          "im2",
          wall_time=2,
          step=12,
          encoded_image_string=b"small",
          width=40,
          height=30,
      )
      acc.Reload()
      self.assertEqual(acc.Images("im1"), [im1])
      self.assertEqual(acc.Images("im2"), [im2])
  
imports: import os
  import numpy
  import tensorflow
  from tensorboard.backend.event_processing import event_accumulator
  from tensorboard.compat.proto import config_pb2
  from tensorboard.compat.proto import event_pb2
  from tensorboard.compat.proto import graph_pb2
  from tensorboard.compat.proto import meta_graph_pb2
  from tensorboard.compat.proto import summary_pb2
  from tensorboard.plugins.distribution import compressor
  from tensorboard.util import tensor_util
  from tensorboard.util import test_util
  from tensorboard.util import tb_logging
label_desc: Use image node_id 9 for calling the MockingEventAccumulatorTest obj's underlying member method code with example usage: obj.testImages() without return types