code: def test_roundrobin() -> None:
      output = list(
          tools.roundrobin([1, 2, 3], (x for x in [4, 5, 6, 7]), (8,))
      )
      np.testing.assert_array_equal(output, [1, 4, 8, 2, 5, 3, 6, 7])
  
file_path: nevergrad/nevergrad/common/test_tools.py
imports: import os
  import typing
  import numpy
  from .None import tools
  from .None import testing
label_desc: Use image node_id 2 for calling a global function with example usage: test_roundrobin() without return types