class_docstr: The class defines the interface of nodes modifying tha data flow in the :class:`Pipeline`
  
  Args:
      operation_type: operation defined in the operation repository
      nodes_from: parent nodes where data comes from
      node_data: ``dict`` with :class:`InputData` for fit and predict stage
      kwargs: optional arguments (i.e. logger)
docstr: Returns ``str`` representation of the node
  
  Returns:
      str: string field node operation type
docstr_tok: ["Returns","``","str","``","representation","of","the","node","Returns",":","str",":","string","field","node","operation","type"]
code: def __str__(self) -> str:
      """Returns ``str`` representation of the node
  
      Returns:
          str: string field node operation type
      """
  
      return str(self.operation.operation_type)
  
imports: from __future__ import annotations
  from dataclasses import dataclass
  from typing import Any, List, Optional, Tuple, Union
  import numpy
  from golem.core.dag.linked_graph_node import LinkedGraphNode
  from golem.core.log import default_log
  from golem.core.optimisers.timer import Timer
  from golem.serializers.serializer import register_serializable
  from fedot.core.data.data import InputData, OutputData
  from fedot.core.data.merge.data_merger import DataMerger
  from fedot.core.operations.factory import OperationFactory
  from fedot.core.operations.operation import Operation
  from fedot.core.operations.operation_parameters import OperationParameters
  from fedot.core.repository.operation_types_repository import OperationTypesRepository
  from fedot.core.utils import DEFAULT_PARAMS_STUB, NESTED_PARAMS_LABEL
label_desc: Use image node_id 22 for calling the PipelineNode obj's underlying member method code with example usage: obj.__str__() and returns: str