public Token GetNullDenotation(Token self)
{
if (this.NullDenotationGetter == null)
throw new InvalidOperationException("Unable to invoke null denotation getter: getter is not set.");
if (self.Type != this.TokenType)
throw new ArgumentException("Unable to invoke null denotation getter: invalid self type.", "self");
return this.NullDenotationGetter(self);
}