code: def test_external_versions_popular_packages():
      ev = ExternalVersions()
  
      for modname in (
          "scipy",
          "numpy",
          "mvpa2",
          "sklearn",
          "statsmodels",
          "pandas",
          "matplotlib",
          "psychopy",
          "github",
      ):
          _test_external(ev, modname)
  
      # more of a smoke test
      assert_false(linesep in ev.dumps())
      assert_true(ev.dumps(indent=True).endswith(linesep))
  
imports: import logging
  import pytest
  from os import linesep
  from datalad import __version__
  from datalad.cmd import StdOutErrCapture, WitlessRunner
  from datalad.support.annexrepo import AnnexRepo
  from datalad.support.exceptions import CommandError, MissingExternalDependency, OutdatedExternalDependency
  from datalad.tests.utils_pytest import SkipTest, assert_equal, assert_false, assert_greater, assert_greater_equal, assert_in, assert_not_in, assert_raises, assert_true, create_tree, patch, set_annex_version, swallow_logs, with_tempfile
  from ..external_versions import ExternalVersions, LooseVersion
label_desc: Use image node_id 6 for calling a global function with example usage: test_external_versions_popular_packages() without return types