public override void Append(StringBuilder sb)
{
if (LeftChild == null)
{
sb.Append(FormulaSerializer.EmptyChild);
}
else
{
LeftChild.Append(sb);
}
AppendToken(sb);
if (RightChild == null)
{
sb.Append(FormulaSerializer.EmptyChild);
}
else
{
RightChild.Append(sb);
}
}
