code: protected JCalValue _writeJson(T property, WriteContext context) {
  		String value = writeText(property, context);
  		return JCalValue.single(value);
  	}
docs: <p>
  Marshals a property's value to a JSON data stream (jCal).
  </p>
  <p>
  This method should be overridden by child classes that wish to support
  jCal. The default implementation of this method will create a jCard
  property that has a single JSON string value (generated by the
  {@link #writeText} method).
  </p>
  @param property the property
  @param context the context
  @return the marshalled value
  @throws SkipMeException if the property should not be written to the data
  stream