// create an XML node for a book XmlNode* book = new XmlNode("book"); // add some child nodes XmlNode* title = book->addChild("title"); title->setValue("The Great Gatsby"); XmlNode* author = book->addChild("author"); author->setValue("F. Scott Fitzgerald"); // get the next sibling of the title node XmlNode* next = title->nextSibling(); // next is now a pointer to the author nodeIn this example, we create an XML node for a book and add some child nodes to it. We then use the nextSibling method to get the next sibling of the title node, which is the author node. It is difficult to determine the package library without more context, but one possible candidate is the tinyxml2 library.