How to use the xmlschema.compat.urlsplit function in xmlschema

while x.startswith('file:////'):
            x = x.replace('file:////', 'file:///', 1)
        if urlsplit(x).scheme in {'', 'file'}:
            x = x.replace('#', '%23')
        return x

    url = filter_url(url)

    if base_url is not None:
        base_url = filter_url(base_url)
        base_url_parts = urlsplit(base_url)
        base_url = add_trailing_slash(base_url_parts)
        if base_url_parts.scheme not in uses_relative:
            base_url_parts = urlsplit('file:///{}'.format(base_url))
        else:
            base_url_parts = urlsplit(base_url)

        if base_url_parts.scheme not in ('', 'file'):
            url = urljoin(base_url, url)
        else:
            url_parts = urlsplit(url)
            if url_parts.scheme not in ('', 'file'):
                url = urljoin(base_url, url)
            elif not url_parts.netloc or base_url_parts.netloc == url_parts.netloc:
                # Join paths only if host parts (netloc) are equal, using the os.path.join
                # instead of urljoin for path normalization.
                url = urlunsplit((
                    '',
                    base_url_parts.netloc,
                    os.path.normpath(os.path.join(base_url_parts.path, url_parts.path)),
                    url_parts.query,
                    url_parts.fragment,

while x.startswith('//'):
            x = x.replace('//', '/', 1)
        while x.startswith('file:////'):
            x = x.replace('file:////', 'file:///', 1)
        if urlsplit(x).scheme in {'', 'file'}:
            x = x.replace('#', '%23')
        return x

    url = filter_url(url)

    if base_url is not None:
        base_url = filter_url(base_url)
        base_url_parts = urlsplit(base_url)
        base_url = add_trailing_slash(base_url_parts)
        if base_url_parts.scheme not in uses_relative:
            base_url_parts = urlsplit('file:///{}'.format(base_url))
        else:
            base_url_parts = urlsplit(base_url)

        if base_url_parts.scheme not in ('', 'file'):
            url = urljoin(base_url, url)
        else:
            url_parts = urlsplit(url)
            if url_parts.scheme not in ('', 'file'):
                url = urljoin(base_url, url)
            elif not url_parts.netloc or base_url_parts.netloc == url_parts.netloc:
                # Join paths only if host parts (netloc) are equal, using the os.path.join
                # instead of urljoin for path normalization.
                url = urlunsplit((
                    '',
                    base_url_parts.netloc,
                    os.path.normpath(os.path.join(base_url_parts.path, url_parts.path)),

def is_remote_url(url):
    return isinstance(url, string_base_type) and urlsplit(url).scheme not in ('', 'file')

def filter_url(x):
        x = x.strip().replace('\\', '/')
        while x.startswith('//'):
            x = x.replace('//', '/', 1)
        while x.startswith('file:////'):
            x = x.replace('file:////', 'file:///', 1)
        if urlsplit(x).scheme in {'', 'file'}:
            x = x.replace('#', '%23')
        return x

def filter_url(x):
        x = x.strip().replace('\\', '/')
        while x.startswith('//'):
            x = x.replace('//', '/', 1)
        while x.startswith('file:////'):
            x = x.replace('file:////', 'file:///', 1)
        if urlsplit(x).scheme in {'', 'file'}:
            x = x.replace('#', '%23')
        return x

    url = filter_url(url)

    if base_url is not None:
        base_url = filter_url(base_url)
        base_url_parts = urlsplit(base_url)
        base_url = add_trailing_slash(base_url_parts)
        if base_url_parts.scheme not in uses_relative:
            base_url_parts = urlsplit('file:///{}'.format(base_url))
        else:
            base_url_parts = urlsplit(base_url)

        if base_url_parts.scheme not in ('', 'file'):
            url = urljoin(base_url, url)
        else:
            url_parts = urlsplit(url)
            if url_parts.scheme not in ('', 'file'):
                url = urljoin(base_url, url)
            elif not url_parts.netloc or base_url_parts.netloc == url_parts.netloc:
                # Join paths only if host parts (netloc) are equal, using the os.path.join
                # instead of urljoin for path normalization.
                url = urlunsplit((