pub trait ITokenKeyExprTreeNode<'a, Weight, Token> {
type Tokenized: IKeyExprTreeNode<Weight>;
type TokenizedMut: IKeyExprTreeNodeMut<Weight>;
// Required methods
fn tokenize(&'a self, token: &'a Token) -> Self::Tokenized;
fn tokenize_mut(&'a self, token: &'a mut Token) -> Self::TokenizedMut;
}