code: public void addParameter(final String tag, final Object value) {
  		if (Util.empty(tag)) {
  			throw new IllegalArgumentException("A tag must be provided");
  		}
  
  		TemplateModel model = getOrCreateComponentModel();
  		if (model.parameters == null) {
  			model.parameters = new HashMap<>();
  		}
  		model.parameters.put(tag, value);
  	}
docs: Add a template parameter.
  
  @param tag the tag for the template parameter
  @param value the value for the template parameter