syntax_data: {"ast_node_type":"other","tokens":[{"end":54,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:             // Closures in thir look something akin to
context_before:         if let &ty::FnDef(did, args) = ty.kind() {
context_after:             // `for<'a> extern "rust-call" fn(&'a [closure@...], ()) -> <[closure@...] as FnOnce<()>>::Output {<[closure@...] as Fn<()>>::call}`