docs: protected final void registerDefaultMimeTypes( String... mimeTypes ) {
          assert !initialized : "No default MIME types can be registered after the sequencer has been initialized";
          if (mimeTypes != null && mimeTypes.length != 0 && acceptedMimeTypes.length == 0) {
              // There are no overridden mime types, so we can register the default MIME types ...
              if (acceptedMimeTypesSet == null) acceptedMimeTypesSet = new HashSet<String>();
              for (String mimeType : mimeTypes) {
                  if (mimeType == null) continue;
                  mimeType = mimeType.trim();
                  if (mimeType.length() == 0) continue;
                  acceptedMimeTypesSet.add(mimeType);
              }
          }
      }