src/vs/workbench/contrib/codeEditor/browser/outline/documentSymbolsTree.ts/DocumentSymbolFilter/filter
class DocumentSymbolFilter:	filter(element: DocumentSymbolItem): boolean {
		const outline = OutlineModel.get(element);
		if (!(element instanceof OutlineElement)) {
			return true;
		}
		const configName = DocumentSymbolFilter.kindToConfigName[element.symbol.kind];
		const configKey = `${this._prefix}.${configName}`;
		return this._textResourceConfigService.getValue(outline?.uri, configKey);
	}