'Disjunction of two query dicts {component_alias: filter_query} (OR)
@param first: the first query dict
@param second: the second query dict
@return: the combined dict'

def _or(self, first, second):

    if (not first):
        return second
    if (not second):
        return first
    if (len(first) > 1):
        first = {None: reduce(combine, first.values())}
    if (len(second) > 1):
        second = {None: reduce(combine, second.values())}
    falias = first.keys()[0]
    salias = second.keys()[0]
    alias = (falias if (falias == salias) else None)
    return {alias: (first[falias] | second[salias])}
