How to use the striprtf.striprtf.rtf_to_text function in striprtf

def extract_text(self):
        txt = self.data.decode(DEFAULT_TEXT_ENCODING)

        # Hack to handle Apple's extensions to the RTF format
        txt = txt.replace("\\\n\\\n", "\\\n\\par\n")

        return rtf_to_text(txt)

import glob
from striprtf.striprtf import rtf_to_text

if __name__ == '__main__':
    rtf_files = glob.glob('Documents/*.rtf')
    for rtf_name in rtf_files:
        txt_name = rtf_name.replace('.rtf','.txt')
        txt_file = open(txt_name, "x")
        content_txt = rtf_to_text(open(rtf_name).read())
        txt_file.write(content_txt)
        txt_file.close()

def cleanup_message_body(
    body: AnyStr, body_type: BodyType, size_threshold: int = 0
) -> str:
    # Decode first
    body = decode(body)

    if body_type is BodyType.RTF:
        # Strip formatting
        body = rtf_to_text(body)

    elif body_type is BodyType.HTML:
        # Strip markup
        body = BeautifulSoup(body, "html.parser").get_text()

    # Strip what might be lines of base64 encoded data
    if len(body) > size_threshold:
        body = re.sub(r"^[>\s]*[A-Za-z0-9+/]{76,}\n?", "", body, flags=re.MULTILINE)

    # Strip uuencoded attachments
    if len(body) > size_threshold:
        body = re.sub(r"begin [0-7]{3}.*?end", "", body, flags=re.DOTALL)

    # Strip notes/calendar data
    if len(body) > size_threshold:
        body = re.sub(