How to use the refextract.references.regexs.re_num.search function in refextract

try:
        first_line = docbody[0]
    except IndexError:
        return ref_details, found_title

    # Need to escape to avoid problems like 'References['
    title = re.escape(title)

    mk_with_title_ptns = \
        get_reference_line_numeration_marker_patterns(title)
    mk_with_title_match = \
        regex_match_list(first_line, mk_with_title_ptns)
    if mk_with_title_match:
        mk = mk_with_title_match.group('mark')
        mk_ptn = mk_with_title_match.re.pattern
        m_num = re_num.search(mk)
        if m_num and m_num.group(0) == '1':
            # Mark found
            found_title = True
            ref_details = {
                'marker': mk,
                'marker_pattern': mk_ptn,
                'title_marker_same_line': True
            }
        else:
            ref_details = {
                'marker': mk,
                'marker_pattern': mk_ptn,
                'title_marker_same_line': True
            }

    return ref_details, found_title