code: public void writeProperty(String propertyName, ICalDataType dataType, JCalValue value) throws IOException {
  		writeProperty(propertyName, new ICalParameters(), dataType, value);
  	}
docs: Writes a property to the current component.
  @param propertyName the property name (e.g. "version")
  @param dataType the property's data type (e.g. "text")
  @param value the property value
  @throws IllegalStateException if there are no open components (
  {@link #writeStartComponent(String)} must be called first) or if the last
  method called was {@link #writeEndComponent()}.
  @throws IOException if there's an I/O problem