src/vs/workbench/api/browser/mainThreadEditor.ts/MainThreadTextEditor/setConfiguration
class MainThreadTextEditor:	public setConfiguration(newConfiguration: ITextEditorConfigurationUpdate): void {
		this._setIndentConfiguration(newConfiguration);

		if (!this._codeEditor) {
			return;
		}

		if (newConfiguration.cursorStyle) {
			const newCursorStyle = cursorStyleToString(newConfiguration.cursorStyle);
			this._codeEditor.updateOptions({
				cursorStyle: newCursorStyle
			});
		}

		if (typeof newConfiguration.lineNumbers !== 'undefined') {
			let lineNumbers: 'on' | 'off' | 'relative';
			switch (newConfiguration.lineNumbers) {
				case RenderLineNumbersType.On:
					lineNumbers = 'on';
					break;
				case RenderLineNumbersType.Relative:
					lineNumbers = 'relative';
					break;
				default:
					lineNumbers = 'off';
			}
			this._codeEditor.updateOptions({
				lineNumbers: lineNumbers
			});
		}
	}