code: public void bind(FloatProperty property, String key) {
  		if (prefs.get(validateKey(key), null) != null) {
  			property.set(prefs.getFloat(key, Float.NaN));
  		}
  		property.addListener(o -> prefs.putFloat(key, property.getValue()));
  	}
docs: @see #bind(ObjectProperty, String)
  
  @param property
  {@link Property} to bind
  @param key
  unique application store key