class_docstr: Approximately computes unique values on the PCollection.
code: def __init__(
      self,
      top_k: int,
      input_dtype: tf.dtypes.DType,
      output_pylist: bool = False,
  ):
      self._top_k = top_k
      self._input_dtype = input_dtype
      self._output_pylist = output_pylist
  
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 1 to create a new _VocabularyCombiner object from inherited base classes: analyzer_nodes with example: obj = _VocabularyCombiner(top_k, input_dtype, output_pylist)