code: protected void _writeXml(T property, XCalElement element, WriteContext context) {
  		String value = writeText(property, context);
  		ICalDataType dataType = dataType(property, ICalVersion.V2_0);
  		element.append(dataType, value);
  	}
docs: <p>
  Marshals a property's value to an XML element (xCal).
  </p>
  <p>
  This method should be overridden by child classes that wish to support
  xCal. The default implementation of this method will append one child
  element to the property's XML element. The child element's name will be
  that of the property's data type (retrieved using the {@link #dataType}
  method), and the child element's text content will be set to the
  property's marshalled plain-text value (retrieved using the
  {@link #writeText} method).
  </p>
  @param property the property
  @param element the property's XML element
  @param context the context
  @throws SkipMeException if the property should not be written to the data
  stream