code: def test_get_compound_mask_correct():
      """Checking whether the procedure for combining lists with keys is
      performed correctly for features_mask"""
  
      synthetic_mask = {
          "input_ids": [0, 0, 1, 1],
          "flow_lens": [1, 1, 0, 0],
      }
      output_example = OutputData(
          idx=[0, 0],
          features=[0, 0],
          predict=[0, 0],
          task=Task(TaskTypesEnum.regression),
          target=[0, 0],
          data_type=DataTypesEnum.table,
          supplementary_data=SupplementaryData(
              features_mask=synthetic_mask
          ),
      )
  
      mask = output_example.supplementary_data.compound_mask
  
      assert ("01", "01", "10", "10") == tuple(mask)
  
file_path: FEDOT/test/unit/data/test_supplementary_data.py
imports: import numpy
  import pytest
  from fedot.core.data.data import OutputData
  from fedot.core.data.merge.data_merger import DataMerger
  from fedot.core.data.merge.supplementary_data_merger import SupplementaryDataMerger
  from fedot.core.data.supplementary_data import SupplementaryData
  from fedot.core.pipelines.node import PipelineNode
  from fedot.core.pipelines.pipeline import Pipeline
  from fedot.core.repository.dataset_types import DataTypesEnum
  from fedot.core.repository.tasks import Task, TaskTypesEnum
  from fedot.preprocessing.data_types import TYPE_TO_ID
  from test.unit.data.test_data_merge import unequal_outputs_table
  from test.unit.tasks.test_regression import get_synthetic_regression_data
label_desc: Use image node_id 5 for calling a global function with example usage: test_get_compound_mask_correct() without return types