code: def drop_elements(
      output: OutputData, fraction_dropped=0.2, with_repetitions=False
  ) -> OutputData:
      num_left = int(len(output.idx) * (1 - fraction_dropped))
      idx_short = np.sort(
          np.random.choice(
              output.idx, size=num_left, replace=with_repetitions
          )
      )
      output_short = OutputData(
          idx=idx_short,
          features=output.features[idx_short],
          predict=output.predict[idx_short],
          target=output.target[idx_short] if output.target else None,
          task=output.task,
          data_type=output.data_type,
      )
      return output_short
  
file_path: FEDOT/test/unit/data/test_data_merge_ts.py
imports: from itertools import product
  import numpy
  import pytest
  from fedot.core.data.data import OutputData
  from fedot.core.data.merge.data_merger import DataMerger
  from fedot.core.pipelines.pipeline_builder import PipelineBuilder
  from fedot.core.repository.dataset_types import DataTypesEnum
  from fedot.core.repository.tasks import Task, TaskTypesEnum, TsForecastingParams
  from fedot.utilities.synth_dataset_generator import generate_synthetic_data
  from test.unit.data_operations.test_data_operations_implementations import get_time_series
label_desc: Use image node_id 3 for calling a global function with example usage: drop_elements(output, fraction_dropped, with_repetitions) and returns: output_short