presto-main/src/main/java/io/prestosql/operator/aggregation/state/KeyValuePairsStateFactory.java/KeyValuePairsStateFactory/KeyValuePairsStateFactory
class KeyValuePairsStateFactory:    public KeyValuePairsStateFactory(Type keyType, Type valueType)
    {
        this.keyType = keyType;
        this.valueType = valueType;
    }