aggregate, setting allowDiskUse

in the incubator ODM for mongo db I can see the options in the constructor but for the life of me I cant seem to figure out how to set options from the static method of ::aggragate() when using it in the context of a Phalcon\Mvc\MongoCollection (model)

so using:

$statusRes = somemodel::aggregate([
                ['$match' => something],
                ['$group' => something],
                ['$sort' => ['something' => -1]]
        ])

where do i set an options array? I have tried in the aggregate array and it wont take it, outside the array and fails since it can only take 1 param (of array).