code: def test_data_merge_ts_multivariate():
      ts1 = get_output_timeseries(for_predict=False)
      ts2 = get_output_timeseries(for_predict=False)
      merged_ts = DataMerger.get([ts1, ts2]).merge()
  
      assert merged_ts.data_type == DataTypesEnum.ts
      expected_shape = (len(ts1.idx), 2)
      assert merged_ts.features.shape == expected_shape
  
      ts1 = get_output_timeseries(num_variables=2, for_predict=False)
      ts2 = get_output_timeseries(num_variables=3, for_predict=False)
      merged_ts = DataMerger.get([ts1, ts2]).merge()
  
      assert merged_ts.data_type == DataTypesEnum.ts
      expected_shape = (len(ts1.idx), 5)
      assert merged_ts.features.shape == expected_shape
  
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 7 for calling a global function with example usage: test_data_merge_ts_multivariate() without return types