src/vs/workbench/services/search/common/searchService.ts/SearchService/groupFolderQueriesByScheme
class SearchService:	private groupFolderQueriesByScheme(query: ISearchQuery): Map<string, IFolderQuery[]> {
		const queries = new Map<string, IFolderQuery[]>();

		query.folderQueries.forEach(fq => {
			const schemeFQs = queries.get(fq.folder.scheme) || [];
			schemeFQs.push(fq);

			queries.set(fq.folder.scheme, schemeFQs);
		});

		return queries;
	}