docs: public void addAll(Configuration other, String prefix) {
  		final StringBuilder bld = new StringBuilder();
  		bld.append(prefix);
  		final int pl = bld.length();
  
  		synchronized (this.confData) {
  			synchronized (other.confData) {
  				for (Map.Entry<String, Object> entry : other.confData.entrySet()) {
  					bld.setLength(pl);
  					bld.append(entry.getKey());
  					this.confData.put(bld.toString(), entry.getValue());
  				}
  			}
  		}
  	}