Pretty print the contents of a binary search tree

Bst.cs

public void Print()
{
	Queue<Node<T>?> nodes = new Queue<Node<T>?>();
	Queue<Node<T>?> newNodes = new Queue<Node<T>?>();
	nodes.Enqueue(Root);
	int depth = 0;

	bool exitCondition = false;
	while (nodes.Count > 0 && !exitCondition)
	{
		depth++;
		newNodes = new Queue<Node<T>?>();

		string xs = "[";
		foreach (var maybeNode in nodes)
		{
			string data = maybeNode == null ? " " : "" + maybeNode.Data;
			if (maybeNode == null)
			{
				xs += "_, ";
				newNodes.Enqueue(null);
				newNodes.Enqueue(null);
			}
			else
			{
				Node<T> node = maybeNode;
				string s = node.Data.ToString();
				xs += s.Substring(0, Math.Min(4, s.Length)) + ", ";
				if (node.LeftChild != null) newNodes.Enqueue(node.LeftChild);
				else newNodes.Enqueue(null);
				if (node.RightChild != null) newNodes.Enqueue(node.RightChild);
				else newNodes.Enqueue(null);
			}
		}
		xs = xs.Substring(0, xs.Length - 2) + "]";

		Console.WriteLine(xs);

		nodes = newNodes;
		exitCondition = true;
		foreach (var m in nodes)
		{
			if (m != null) exitCondition = false;
		}
	}
}