code: def all_preprocessed(self, *, is_obligatory: bool = True) -> bool:
      return all(
          output.supplementary_data.obligatorily_preprocessed
          if is_obligatory
          else output.supplementary_data.optionally_preprocessed
          for output in self.outputs
      )
  
file_path: FEDOT/fedot/core/data/merge/supplementary_data_merger.py
imports: from typing import Dict, List
  import numpy
  from golem.core.log import default_log
  from fedot.core.data.data import OutputData
  from fedot.core.data.supplementary_data import SupplementaryData
  from fedot.core.repository.dataset_types import DataTypesEnum
  from fedot.preprocessing.data_types import TableTypesCorrector
label_desc: Use image node_id 4 for calling the SupplementaryDataMerger obj's underlying member method code with example usage: obj.all_preprocessed() and returns: all