src/vs/editor/common/config/editorOptions.ts/GuideOptions/validate
class GuideOptions:	public validate(_input: any): InternalGuidesOptions {
		if (!_input || typeof _input !== 'object') {
			return this.defaultValue;
		}
		const input = _input as IGuidesOptions;
		return {
			bracketPairs: primitiveSet(input.bracketPairs, this.defaultValue.bracketPairs, [true, false, 'active']),
			bracketPairsHorizontal: primitiveSet(input.bracketPairsHorizontal, this.defaultValue.bracketPairsHorizontal, [true, false, 'active']),
			highlightActiveBracketPair: boolean(input.highlightActiveBracketPair, this.defaultValue.highlightActiveBracketPair),

			indentation: boolean(input.indentation, this.defaultValue.indentation),
			highlightActiveIndentation: primitiveSet(input.highlightActiveIndentation, this.defaultValue.highlightActiveIndentation, [true, false, 'always']),
		};
	}