src/vs/workbench/contrib/terminal/browser/terminalService.ts/TerminalService/requestStartExtensionTerminal
class TerminalService:	requestStartExtensionTerminal(proxy: ITerminalProcessExtHostProxy, cols: number, rows: number): Promise<ITerminalLaunchError | undefined> {
		// The initial request came from the extension host, no need to wait for it
		return new Promise<ITerminalLaunchError | undefined>(callback => {
			this._onDidRequestStartExtensionTerminal.fire({ proxy, cols, rows, callback });
		});
	}