void () { VirtualFile first = tempDirectory.newVirtualDirectory("first/"); VirtualFile second = tempDirectory.newVirtualDirectory("second/"); assertNothingToRescan(); libraryRootsId1.add(first); libraryRootsId1.add(second); assertRescanningLibraries(YES, first, second); assertNothingToRescan(); libraryRootsId1.clear(); libraryRootsId1.add(second); libraryRootsId1.add(first); assertNothingToRescan(); }