template<class T> class ListNode { public: void setSibling(T sibling) { _list_node_sibling = sibling; } const T getSi

This is a C++ template class definition for a ListNode, which is a basic building block for linked lists. The class has one template parameter, T, which represents the type of data that will be stored in the list node. The class has two public methods: setSibling and getSibling. The setSibling method takes a parameter of type T and sets the _list_node_sibling member variable to that value. The getSibling method returns the value of _list_node_sibling as a const reference to type T. The class also has one protected member variable, _list_node_sibling, which is of type T and represents a pointer to the next node in the linked list. Overall, this class provides a simple implementation of a linked list node that can be used with any type of data.