I expect it should work:
```
:) select CAST(CAST('{"x" : 1}', 'Object(\'json\')'), 'Object(Nullable(\'json\'))')

SELECT CAST(CAST('{"x" : 1}', 'Object(\'json\')'), 'Object(Nullable(\'json\'))')

Query id: fb057b45-b72a-4d22-9b38-a3136cdf2465


0 rows in set. Elapsed: 0.002 sec.

Received exception from server (version 22.5.1):
Code: 53. DB::Exception: Received from localhost:9000. DB::Exception: Cast to Object can be performed only from flatten named Tuple, Map or String. Got: Object('json'): While processing CAST(CAST('{"x" : 1}', 'Object(\'json\')'), 'Object(Nullable(\'json\'))'). (TYPE_MISMATCH)
```

@CurtizJ what do you think?
{
        if (checkAndGetDataType<DataTypeString>(from_type.get()))
        {
            return &ConvertImplGenericFromString<ColumnString>::execute;
        }
        return createWrapper<ToDataType>(from_type, to_type, requested_result_is_nullable);
    }
    WrapperType createUInt8ToBoolWrapper(const DataTypePtr from_type, const DataTypePtr to_type) const
    {
        return [from_type, to_type] (ColumnsWithTypeAndName & arguments, const DataTypePtr &, const ColumnNullable *, size_t ) -> ColumnPtr
        {
            
            
            
            auto res_column = to_type->createColumn();
            const auto & data_from = checkAndGetColumn<ColumnUInt8>(arguments[0].column.get())->getData();
            auto & data_to = assert_cast<ColumnUInt8 *>(res_column.get())->getData();
            data_to.resize(data_from.size());
            for (size_t i = 0; i != data_from.size(); ++i)
                data_to[i] = static_cast<bool>(data_from[i]);
            return res_column;
        };
    }
    static WrapperType createStringWrapper(const DataTypePtr & from_type)
    {
        FunctionPtr function = FunctionToString::create();
        return createFunctionAdaptor(function, from_type);
    }
    WrapperType createFixedStringWrapper(const DataTypePtr & from_type, const size_t N) const