def open_form(cik, acc_num):
    """
    For a given cik and accession number, opens the index page in default browser for the
    associated SEC form.
    """
    acc_num = _drop_dashes(acc_num)
    webbrowser.open_new_tab(
        f"{SEC_ARCHIVE_URL}/{cik}/{acc_num}/{_add_dashes(acc_num)}-index.html"
    )

    For a given cik and accession number, opens the index page in default browser for the
    associated SEC form.
    
llama-index-integrations/readers/llama-index-readers-sec-filings/llama_index/readers/sec_filings/prepline_sec_filings/fetch.py