code: def test_singleton_input(self):
      pb = self.histogram("twelve", [12])
      buckets = tensor_util.make_ndarray(pb.value[0].tensor)
      # By default there will be 30 buckets.
      expected_buckets = np.array(
          [[12, 12, 0] for _ in range(29)] + [[12, 12, 1]]
      )
      np.testing.assert_allclose(buckets, expected_buckets)
  
imports: import glob
  import os
  import numpy
  import tensorflow
  from tensorboard.compat import tf2
  from tensorboard.compat.proto import summary_pb2
  from tensorboard.plugins.histogram import metadata
  from tensorboard.plugins.histogram import summary
  from tensorboard.util import tensor_util
label_desc: Use image node_id 10 for calling the SummaryV3OpTest obj's underlying member method code with example usage: obj.test_singleton_input() without return types