internal virtual void AppendTreeToString(StringBuilder b, int indent)
{
b.AppendLine(ToString());
indent += 2;
if (Left != null)
{
b.Append(' ', indent);
b.Append("L: ");
Left.AppendTreeToString(b, indent);
}
if (Right != null)
{
b.Append(' ', indent);
b.Append("R: ");
Right.AppendTreeToString(b, indent);
}
}
