{"ast_node_type":"other","tokens":[{"end":142,"kind":"keyword","start":0,"text":"//"}]}
                // https://github.com/rust-lang/rust/blob/a58b1ed44f5e06976de2bdc4d7dc81c36a96934f/src/librustc_expand/mbe/macro_rules.rs#L558
                // Checks that no repetition which could match an empty token
                let lsh_is_empty_seq = separator.is_none() && subtree.iter().all(|child_op| {