class_docstr: Represents a single transform function in a MapTransformer.
class_docstr_tok: ["Represents","a","single","transform","function","in","a","MapTransformer","."]
code: def output_type(self) -> MapTransformFnDataType:
      return self._output_type
  
imports: import itertools
  from abc import abstractmethod
  from enum import Enum
  from typing import Any, Callable, Dict, Iterable, List, Optional, TypeVar, Union
  from ray.data._internal.block_batching.block_batching import batch_blocks
  from ray.data._internal.execution.interfaces.task_context import TaskContext
  from ray.data._internal.output_buffer import BlockOutputBuffer
  from ray.data.block import Block, BlockAccessor, DataBatch
label_desc: Use image node_id 4 for calling the MapTransformFn obj's underlying member method code with example usage: obj.output_type() and returns: self