code: def test_call_from_parser_pos_arg_underscore(how):
      kwds = {"doc": "pos_arg doc"}
      if how == "dest":
          kwds["dest"] = "pos_arg"
      elif how == "args":
          kwds["args"] = ("pos_arg",)
      elif how != "bare":
          raise AssertionError("Unrecognized how: {}".format(how))
  
      class Cmd(Interface):
          _params_ = dict(pos_arg=Parameter(**kwds))
  
          def __call__(pos_arg, **kwargs):
              return pos_arg
  
      parser = argparse.ArgumentParser()
      parser_add_common_options(parser)
      setup_parser_for_interface(parser, Cmd)
      args = parser.parse_args(["val"])
      eq_(call_from_parser(Cmd, args), "val")
  
file_path: datalad/datalad/cli/tests/test_exec.py
imports: import argparse
  from argparse import Namespace
  import pytest
  from datalad.interface.base import Interface
  from datalad.support.param import Parameter
  from datalad.tests.utils_pytest import assert_not_in, eq_, patch_config
  from datalad.utils import updated
  from ..exec import _get_result_filter, call_from_parser
  from ..parser import parser_add_common_options, setup_parser_for_interface
label_desc: Use image node_id 8 for calling a global function with example usage: test_call_from_parser_pos_arg_underscore(how) and returns: pos_arg