def METHOD_NAME(cls, document_url) -> str:
    """
    Get the public URL for VitalSource book viewer.
    :param document_url: `vitalsource://` type URL identifying the document
    """
    loc = VSBookLocation.from_document_url(document_url)
    return f"https://hypothesis.vitalsource.com/books/{loc.book_id}/cfi/{loc.cfi}"