syntax_data: {"ast_node_type":"other","tokens":[{"end":39,"kind":"keyword","start":0,"text":"[\"syn\""}]}
source_snippet:             ["syn" | "proc_macro2", ..]
context_before:             // These are the types from Rust core ecosystem
context_after:             | ["core" | "std", "task", "LocalWaker" | "Waker"]