How to use the idutils.is_arxiv function in idutils

def _is_arxiv(obj):
    """Return ``True`` if ``obj`` contains an arXiv identifier.

    The ``idutils`` library only handles arXiv identifiers, e.g. strings
    of the form ``arXiv:yymm.xxxxx``, but we sometimes have to deal with
    arXiv references, which might contain more information separated by
    a space. Therefore this helper wraps ``idutils`` to support this case.
    """
    arxiv_test = obj.split()
    if not arxiv_test:
        return False
    return idutils.is_arxiv(arxiv_test[0])

def arxiv_syntax_validation(form, field):
    """Validate ArXiv ID syntax."""
    message = "The provided ArXiv ID is invalid - it should look \
                similar to 'hep-th/9711200' or '1207.7235'."

    if field.data and not is_arxiv(field.data):
        raise StopValidation(message)

def arxiv_syntax_validation(form, field):
    """Validate ArXiv ID syntax."""
    message = "The provided ArXiv ID is invalid - it should look \
                similar to 'hep-th/9711200' or '1207.7235'."

    if field.data and not is_arxiv(field.data):
        raise StopValidation(message)