public interface ITreeBuilder { void AddNode(int parentValue, int nodeValue); void DeleteNode(int nodeValue); void PrintTree(); }This code snippet represents a basic implementation of the ITreeBuilder interface. It defines three methods - AddNode, DeleteNode, and PrintTree. The AddNode method takes two parameters: the value of the parent node and the value of the new node to be added. The DeleteNode method takes a single parameter: the value of the node to be deleted. The PrintTree method prints out the tree structure. Package library: This interface is not necessarily tied to a specific package library, as it can be implemented in various environments. However, it may be commonly found in libraries for data structures or programming challenges.