docs: public static void setVerbose(java.util.logging.Level verbose) {
      if(verbose.intValue() <= Level.VERBOSE.intValue()) {
        // decrease to VERBOSE if it was higher, otherwise further to
        // VERYVERBOSE
        if(LOGGER_GLOBAL_TOP.getLevel() == null || LOGGER_GLOBAL_TOP.getLevel().intValue() > verbose.intValue()) {
          LOGGER_GLOBAL_TOP.setLevel(verbose);
        }
        if(LOGGER_ELKI_TOP.getLevel() == null || LOGGER_ELKI_TOP.getLevel().intValue() > verbose.intValue()) {
          LOGGER_ELKI_TOP.setLevel(verbose);
        }
      }
      else {
        // re-increase to given level if it was verbose or "very verbose".
        if(LOGGER_GLOBAL_TOP.getLevel() != null && (//
        Level.VERBOSE.equals(LOGGER_GLOBAL_TOP.getLevel()) || //
            Level.VERYVERBOSE.equals(LOGGER_GLOBAL_TOP.getLevel()) //
        )) {
          LOGGER_GLOBAL_TOP.setLevel(verbose);
        }
        if(LOGGER_ELKI_TOP.getLevel() != null && (//
        Level.VERBOSE.equals(LOGGER_ELKI_TOP.getLevel()) || //
            Level.VERYVERBOSE.equals(LOGGER_ELKI_TOP.getLevel()) //
        )) {
          LOGGER_ELKI_TOP.setLevel(verbose);
        }
      }
    }