code: def test_choose_chains(
      n_points, tune, expected_length, expected_n_traces
  ):
      trace_0 = np.arange(n_points[0])
      trace_1 = np.arange(n_points[1])
      trace_2 = np.arange(n_points[2])
      traces, length = _choose_chains(
          [trace_0, trace_1, trace_2], tune=tune
      )
      assert length == expected_length
      assert expected_n_traces == len(traces)
  
file_path: pymc/tests/backends/test_base.py
imports: import numpy
  import pytest
  import pymc
  from pymc.backends import _init_trace
  from pymc.backends.base import _choose_chains
label_desc: Use image node_id 1 for calling a global function with example usage: test_choose_chains(n_points, tune, expected_length, expected_n_traces) without return types