```
SELECT *
FROM system.dictionaries
WHERE name LIKE 'XXXX%'

Row 1:
──────
database:                    default
name:                        XXXX_dict
uuid:                        00000000-0000-0000-0000-000000000000
status:                      LOADED
origin:                      default.XXXX_dict
type:                        Polygon
key:                         (Array(Array(Array(Array(Float64)))))
attribute.names:             ['name','id']
attribute.types:             ['String','String']
bytes_allocated:             0
query_count:                 0
hit_rate:                    1
element_count:               433731
load_factor:                 1
source:                      ClickHouse: default.XXXX
lifetime_min:                60
lifetime_max:                1800
loading_start_time:          2021-03-11 00:07:52
last_successful_update_time: 2021-03-11 00:08:24
loading_duration:            31.595
last_exception:
```
{
    null_values.emplace_back(T(null_value.get<NearestFieldType<T>>()));
}
void IPolygonDictionary::appendNullValue(AttributeUnderlyingType type, const Field & null_value)
{
    switch (type)
    {
        case AttributeUnderlyingType::utUInt8:
            appendNullValueImpl<UInt8>(null_value);
            break;
        case AttributeUnderlyingType::utUInt16:
            appendNullValueImpl<UInt16>(null_value);
            break;
        case AttributeUnderlyingType::utUInt32:
            appendNullValueImpl<UInt32>(null_value);
            break;
        case AttributeUnderlyingType::utUInt64:
            appendNullValueImpl<UInt64>(null_value);
            break;
        case AttributeUnderlyingType::utUInt128:
            appendNullValueImpl<UInt128>(null_value);
            break;
        case AttributeUnderlyingType::utInt8:
            appendNullValueImpl<Int8>(null_value);
            break;