How to use the stestr.commands.load.load function in stestr

def run_tests():
            if not dynamic or cmd.concurrency == 1:
                run_procs = [('subunit',
                              output.ReturnCodeToSubunit(
                                  proc,
                                  dynamic=False)) for proc in cmd.run_tests()]
            else:
                run_procs = [('subunit',
                              output.ReturnCodeToSubunit(
                                  os.fdopen(proc['stream']),
                                  proc['proc'])) for proc in cmd.run_tests()]
            if not run_procs:
                stdout.write("The specified regex doesn't match with anything")
                return 1
            return load.load((None, None), in_streams=run_procs,
                             subunit_out=subunit_out,
                             repo_type=repo_type,
                             repo_url=repo_url, run_id=combine_id,
                             pretty_out=pretty_out, color=color, stdout=stdout,
                             abbreviate=abbreviate,
                             suppress_attachments=suppress_attachments,
                             all_attachments=all_attachments)

def run_tests():
            run_proc = [('subunit', output.ReturnCodeToSubunit(
                subprocess.Popen(run_cmd, shell=True,
                                 stdout=subprocess.PIPE)))]
            return load.load(in_streams=run_proc,
                             subunit_out=subunit_out,
                             repo_type=repo_type,
                             repo_url=repo_url, run_id=combine_id,
                             pretty_out=pretty_out,
                             color=color, stdout=stdout, abbreviate=abbreviate,
                             suppress_attachments=suppress_attachments,
                             all_attachments=all_attachments)

if pdb:
        ids = pdb
        if '::' in ids:
            ids = ids.replace('::', '.')
        if ids.find('/') != -1:
            root = ids.replace('.py', '')
            ids = root.replace('/', '.')
        runner = subunit_run.SubunitTestRunner
        stream = io.BytesIO()
        program.TestProgram(module=None, argv=['stestr', ids],
                            testRunner=functools.partial(runner,
                                                         stdout=stream))
        stream.seek(0)
        run_proc = [('subunit', stream)]
        return load.load(in_streams=run_proc,
                         subunit_out=subunit_out,
                         repo_type=repo_type,
                         repo_url=repo_url, run_id=combine_id,
                         pretty_out=pretty_out,
                         color=color, stdout=stdout, abbreviate=abbreviate,
                         suppress_attachments=suppress_attachments,
                         all_attachments=all_attachments)

    if failing or analyze_isolation:
        ids = _find_failing(repo)
    else:
        ids = None
    if load_list:
        list_ids = set()
        # Should perhaps be text.. currently does its own decode.
        with open(load_list, 'rb') as list_file: