function storeOldData(db, step, condition){
        var Collection = getCollectionForStep(db, step);
        var options = step.options
            ? utils.xcode(step.options)
            : step.type === constants.REMOVE ? {multi: true} : null;
        var query = Collection.find(condition);
        var searchQuery = options && options.multi === true
            ? query
            : query.limit(1);

        return searchQuery.toArray().then(function(result){
            step.dataStore = result;
        });
    }
This function stores data that's about to be
changed by a step, for rollback purposes

@param db native db
@param step the step
@param condition literal obj rep of the step's condition

@returns {Promise|*}