def elementStream():
    """ Preferred method to construct an ElementStream

    Uses Expat-based stream if available, and falls back to Sux if necessary.
    """
    try:
        es = ExpatElementStream()
        return es
    except __HOLE__:
        if SuxElementStream is None:
            raise Exception("No parsers available :(")
        es = SuxElementStream()
        return es
dataset/ETHPy150Open nlloyd/SubliminalCollaborator/libs/twisted/words/xish/domish.py/elementStream