Python representation of a mzML userParam = tuple(name, value,
    unitAccession, type)

    :param attributes: #TODO: docstring

    :returns: #TODO: docstring

def userParamFromDict(attributes):
    """Python representation of a mzML userParam = tuple(name, value,
    unitAccession, type)

    :param attributes: #TODO: docstring

    :returns: #TODO: docstring
    """
    keys = ['name', 'value', 'unitAccession', 'type']
    return tuple(attributes[key] if key in attributes else None for key in keys)