code: public XAttributeBoolean createAttributeBoolean(String key, boolean value,
  			XExtension extension) {
  		return new XAttributeBooleanImpl(intern(key), value, extension);
  	}
docs: /* (non-Javadoc)
  @see org.deckfour.xes.model.factory.XModelFactory#createAttributeBoolean(java.lang.String, boolean, org.deckfour.xes.extension.XExtension)