class_docstr: Approximately computes unique values on the PCollection.
code: def create_accumulator(self) -> sketches.MisraGriesSketch:
      return sketches.MisraGriesSketch(
          self._top_k,
          order_on_tie=sketches.MisraGriesSketch.OrderOnTie.ReverseLexicographical,
      )
  
imports: from typing import Any, Collection, List, Optional, Tuple, Union, Iterable, Sequence
  import numpy
  import pyarrow
  import tensorflow
  from tensorflow_transform import analyzer_nodes
  from tensorflow_transform import analyzers
  from tensorflow_transform import common
  from tensorflow_transform import common_types
  from tensorflow_transform import nodes
  from tensorflow_transform import tf_utils
  from tfx_bsl import sketches
  from tfx_bsl.types import tfx_namedtuple
  from typing_extensions import Protocol
label_desc: Use image node_id 2 for calling the _VocabularyCombiner obj's underlying member method code with example usage: obj.create_accumulator() and returns: sketches