src/vs/base/browser/ui/inputbox/inputBox.ts/InputBox/hideMessage
class InputBox:	public hideMessage(): void {
		this.message = null;

		this.element.classList.remove('info');
		this.element.classList.remove('warning');
		this.element.classList.remove('error');
		this.element.classList.add('idle');

		this._hideMessage();
		this.applyStyles();
	}