src/vs/platform/terminal/node/ptyService.ts/PersistentTerminalProcess/start
class PersistentTerminalProcess:	async start(): Promise<ITerminalLaunchError | undefined> {
		this._logService.trace('persistentTerminalProcess#start', this._persistentProcessId, this._isStarted);
		if (!this._isStarted) {
			const result = await this._terminalProcess.start();
			if (result) {
				// it's a terminal launch error
				return result;
			}
			this._isStarted = true;
		} else {
			this._onProcessReady.fire({ pid: this._pid, cwd: this._cwd, requiresWindowsMode: isWindows && getWindowsBuildNumber() < 21376 });
			this._onProcessTitleChanged.fire(this._terminalProcess.currentTitle);
			this._onProcessShellTypeChanged.fire(this._terminalProcess.shellType);
			this.triggerReplay();
		}
		return undefined;
	}