https://clickhouse-test-reports.s3.yandex.net/20492/c5b96a522e29b38eae3f6c2d945540dd234e3c34/fuzzer_msan/server.log

```
for i in {1..100}; do clickhouse-client --query "SELECT toUInt8(assumeNotNull(cast(cast(NULL, 'Nullable(String)'), 'Nullable(Enum8(\'Hello\' = 1))')))"; done

160
224
128
192
64
64
32
160
128
192
128
224
128
160
0
96
64
32
192
224
64
96
224
96
128
192
192
128
...
```
{
    Throw,  
    Zero,   
    Null    
};
enum class ConvertFromStringParsingMode
{
    Normal,
    BestEffort,  
    BestEffortUS
};
template <typename FromDataType, typename ToDataType, typename Name,
    ConvertFromStringExceptionMode exception_mode, ConvertFromStringParsingMode parsing_mode>
struct ConvertThroughParsing
{
    static_assert(std::is_same_v<FromDataType, DataTypeString> || std::is_same_v<FromDataType, DataTypeFixedString>,
        "ConvertThroughParsing is only applicable for String or FixedString data types");
    static constexpr bool to_datetime64 = std::is_same_v<ToDataType, DataTypeDateTime64>;
    
    static bool isAllRead(ReadBuffer & in)