512     /**

   513      * Returns a {@code FileTypeDetector} that chains the given array of file

   514      * type detectors. When the {@code implProbeContentType} method is invoked

   515      * then each of the detectors is invoked in turn, the result from the

   516      * first to detect the file type is returned.

   517      */

   518     final FileTypeDetector chain(final AbstractFileTypeDetector... detectors) {

   519         return new AbstractFileTypeDetector() {

   520             @Override

   521             protected String implProbeContentType(Path file) throws IOException {

   522                 for (AbstractFileTypeDetector detector : detectors) {

   523                     String result = detector.implProbeContentType(file);

   524                     if (result != null && !result.isEmpty()) {

   525                         return result;

   526                     }

   527                 }

   528                 return null;

   529             }

   530         };

   531     }