code: protected void appendTextElementIfNotNull(Document doc, Element parent,
  			String elName, Object value) {
  
  		if (value == null) {
  			return;
  		}
  
  		createAndAppendTextElementCheckNull(doc, parent, elName, value);
  	}
docs: Helper to create a new element with name elName and append it to the {@link Element} given by parent if the given
  value is non-null.
  The new {@link Element} will have {@link Text} node containing value.
  
  @param doc
  {@link Document} where parent is located in
  @param parent
  where to append the new element
  @param elName
  the name of the new element.
  @param value
  the value of the {@link Text} node appended to the new element,
  using toString() on the object.