code: public long getLastModified(VirtualFile mountPoint, VirtualFile target) {
          final ZipNode zipNode = getZipNode(mountPoint, target);
          if (zipNode == null) {
              return 0L;
          }
          final File cachedFile = zipNode.cachedFile;
          final JarEntry entry = zipNode.entry;
          return cachedFile != null ? cachedFile.lastModified() : entry == null ? zipTime : entry.getTime();
      }
docs: {@inheritDoc}