Check if self id

OptionalJID returns the JID under the given key. If there's no valid JID under the given key, this will return nil. However, if the attribute is compl

Initialize this value as constant string, without calling destructor.

Appends a new attribute to the node. \param attribute Attribute to append.

Appends a new child node. The appended child becomes the last child. \param child Node to append.