{"ast_node_type":"other","tokens":[{"end":78,"kind":"keyword","start":0,"text":"///"}]}
    /// returned if the look-ahead is any distance past the end of the tokens.
    /// When `dist == 0` then the current token is looked at. `Eof` will be
    pub fn look_ahead<R>(&self, dist: usize, looker: impl FnOnce(&Token) -> R) -> R {