How to use the vcard.vcard_definitions.NEWLINE_CHARACTERS function in vcard

def unfold_vcard_lines(lines):
    """
    Un-split lines in vCard, warning about short lines. RFC 2426 page 8.

    @param lines: List of potentially folded vCard lines
    @return: List of lines, one per property
    """
    property_lines = []
    for index in range(len(lines)):
        line = lines[index]
        if not line.endswith(NEWLINE_CHARACTERS):
            raise VCardLineError(NOTE_INVALID_LINE_SEPARATOR, {'File line': index + 1})

        if len(line) > VCARD_LINE_MAX_LENGTH_RAW:
            warnings.warn('Long line in vCard: {0}'.format(line.encode('utf-8')))

        if line.startswith(' '):
            if index == 0:
                raise VCardLineError(NOTE_CONTINUATION_AT_START, {'File line': index + 1})
            elif len(lines[index - 1]) < VCARD_LINE_MAX_LENGTH_RAW:
                warnings.warn('Short folded line at line {0:d}'.format(index - 1))
            elif line == SPACE_CHARACTER + NEWLINE_CHARACTERS:
                warnings.warn('Empty folded line at line {0:d}'.format(index))
            property_lines[-1] = \
                property_lines[-1][:-len(NEWLINE_CHARACTERS)] + line[1:]
        else:
            property_lines.append(line)

"""
    if filename == '-':
        file_pointer = sys.stdin
    else:
        file_pointer = codecs.open(filename, 'r', 'utf-8')

    contents = file_pointer.read().splitlines(True)

    vcard_text = ''
    result = ''
    try:
        for index in range(len(contents)):
            line = contents[index]
            vcard_text += line

            if line == NEWLINE_CHARACTERS:
                try:
                    vcard = VCard(vcard_text, filename)
                    vcard_text = ''
                    if verbose:
                        print(vcard)
                except VCardError as error:
                    error.context['File'] = filename
                    error.context['File line'] = index
                    err_type = type(error)
                    raise err_type(error.message, error.context)

    except VCardError as error:
        result += str(error)

    if vcard_text != '' and result == '':
        result += 'Could not process entire %s - %i lines remain' % (filename, len(vcard_text.splitlines(False)))

def get_vcard_property_values(values_string):
    """
    Get the property values.

    @param values_string: Multiple value string
    @return: List of values (RFC 2426 page 12)
    """
    values = []

    # Strip line ending
    values_string = values_string[:-len(NEWLINE_CHARACTERS)]

    sub_value_strings = vcard_utils.split_unescaped(values_string, ';')
    for sub in sub_value_strings:
        values.append(get_vcard_property_sub_values(sub))

    return values