aggregation method
Set aggregation functions for aggregate queries.
Example:
.aggregation({
'_count': true,
'_avg': {'price': true, 'rating': true},
'_sum': {'quantity': true},
'_min': {'price': true},
'_max': {'price': true},
})
Implementation
JsonQueryBuilder aggregation(Map<String, dynamic> agg) {
_aggregate = agg;
return this;
}