https://clickhouse-test-reports.s3.yandex.net/17375/99073c26ee2692f8efe2ab14b2d8ae0fd813b80e/fuzzer/fuzzer.log

```
SELECT
    k,
    topK(v)
FROM 
(
    SELECT
        number % 7 AS k,
        arrayMap(x -> arrayMap(x -> if(x = 0, NULL, toString(x)), range(x)), range(intDiv(number, 1))) AS v
    FROM system.numbers
    LIMIT 257
)
GROUP BY k
ORDER BY k ASC
```
{
            writeBinary(key, wb);
            writeVarUInt(count, wb);
            writeVarUInt(error, wb);
        }
        void read(ReadBuffer & rb)
        {
            readBinary(key, rb);
            readVarUInt(count, rb);
            readVarUInt(error, rb);
        }
        
        bool operator> (const Counter & b) const
        {
            return (count > b.count) || (count == b.count && error < b.error);
        }
        TKey key;
        size_t slot;
        size_t hash;
        UInt64 count;
        UInt64 error;
    };
    SpaceSaving(size_t c = 10) : alpha_map(nextAlphaSize(c)), m_capacity(c) {}
    ~SpaceSaving() { destroyElements(); }
    inline size_t size() const
    {
        return counter_list.size();
    }
    inline size_t capacity() const