syntax_data: {"ast_node_type":"other","tokens":[{"end":64,"kind":"keyword","start":0,"text":"ty::IntTy::I32"}]}
source_snippet:                 ty::IntTy::I32 => Some(ty::ClosureKind::FnOnce),
context_before:                 ty::IntTy::I16 => Some(ty::ClosureKind::FnMut),
context_after:                 _ => bug!("cannot convert type `{:?}` to a closure kind", self),