src/vs/editor/common/config/editorOptions.ts/InlineEditorSuggest/validate
class InlineEditorSuggest:	public validate(_input: any): InternalInlineSuggestOptions {
		if (!_input || typeof _input !== 'object') {
			return this.defaultValue;
		}
		const input = _input as IInlineSuggestOptions;
		return {
			enabled: boolean(input.enabled, this.defaultValue.enabled),
			mode: stringSet(input.mode, this.defaultValue.mode, ['prefix', 'subword', 'subwordSmart']),
		};
	}