syntax_data: {"ast_node_type":"other","tokens":[{"end":92,"kind":"keyword","start":0,"text":"self,"}]}
source_snippet:     self, BoundVar, CanonicalPolyFnSig, ClosureSizeProfileData, GenericArgKind, GenericArgs,
context_before: use crate::ty::{
context_after:     GenericArgsRef, Ty, UserArgs, tls,