docs: public long classpathContentsLastModifiedTime() {
          if (closed.get()) {
              throw new IllegalArgumentException("Cannot use a ScanResult after it has been closed");
          }
          long maxLastModifiedTime = 0L;
          if (fileToLastModified != null) {
              final long currTime = System.currentTimeMillis();
              for (final long timestamp : fileToLastModified.values()) {
                  if (timestamp > maxLastModifiedTime && timestamp < currTime) {
                      maxLastModifiedTime = timestamp;
                  }
              }
          }
          return maxLastModifiedTime;
      }