AST-based query fuzzer should randomly modify data types in CREATE TABLE queries, mostly by wrapping in Nullable, Array and LowCardinality.
std::optional<Suggest> suggest;
    bool load_suggestions = false;
    std::vector<String> queries_files; 
    std::vector<String> interleave_queries_files; 
    std::vector<String> cmd_options;
    bool stdin_is_a_tty = false; 
    bool stdout_is_a_tty = false; 
    bool stderr_is_a_tty = false; 
    uint64_t terminal_width = 0;
    String format; 
    bool select_into_file = false; 
    bool select_into_file_and_stdout = false; 
    bool is_default_format = true; 
    size_t format_max_block_size = 0; 
    String insert_format; 
    size_t insert_format_max_block_size = 0; 
    size_t max_client_network_bandwidth = 0; 
    bool has_vertical_output_suffix = false; 
    
    std::vector<std::pair<String, String>> query_id_formats;
    
    Settings cmd_settings;
    SharedContextHolder shared_context;
    ContextMutablePtr global_context;
    
    std::optional<ThreadStatus> thread_status;
    ServerConnectionPtr connection;
    ConnectionParameters connection_parameters;
    
    ReadBufferFromFileDescriptor std_in{STDIN_FILENO};