System.util.collections.OrderedTree.GetMinKey C# (CSharp) Method

        public IComparable GetMinKey()
        {
            OrderedTreeNode treeNode = rbTree;

            if(treeNode == null || treeNode == sentinelNode)
                throw(new InvalidOperationException("Tree is empty"));

            // traverse to the extreme left to find the smallest key
            while(treeNode.Left != sentinelNode)
                treeNode = treeNode.Left;

            lastNodeFound = treeNode;

            return treeNode.Key;
        }