src/vs/editor/common/config/editorOptions.ts/EditorRulers/validate
class EditorRulers:	public validate(input: any): IRulerOption[] {
		if (Array.isArray(input)) {
			const rulers: IRulerOption[] = [];
			for (const _element of input) {
				if (typeof _element === 'number') {
					rulers.push({
						column: EditorIntOption.clampedInt(_element, 0, 0, 10000),
						color: null
					});
				} else if (_element && typeof _element === 'object') {
					const element = _element as IRulerOption;
					rulers.push({
						column: EditorIntOption.clampedInt(element.column, 0, 0, 10000),
						color: element.color
					});
				}
			}
			rulers.sort((a, b) => a.column - b.column);
			return rulers;
		}
		return this.defaultValue;
	}