AST-based query fuzzer should randomly modify data types in CREATE TABLE queries, mostly by wrapping in Nullable, Array and LowCardinality.
bool have_error = false;
    std::list<ExternalTable> external_tables; 
    bool send_external_tables = false;
    NameToNameMap query_parameters; 
    QueryFuzzer fuzzer;
    int query_fuzzer_runs = 0;
    struct
    {
        bool print = false;
        
        UInt64 delay_ms = 0;
        Stopwatch watch;
        
        Block last_block;
    } profile_events;
    QueryProcessingStage::Enum query_processing_stage;
    ClientInfo::QueryKind query_kind;
    bool fake_drop = false;
    struct HostAndPort
    {
        String host;
        std::optional<UInt16> port;
    };
    std::vector<HostAndPort> hosts_and_ports{};
    bool allow_repeated_settings = false;
    bool cancelled = false;
    bool logging_initialized = false;
};
}