syntax_data: {"ast_node_type":"other","tokens":[{"end":50,"kind":"keyword","start":0,"text":"for"}]}
source_snippet:     for pred in param_env.caller_bounds().iter() {
context_before:     // Iterate through all goals in param_env to find the one that has the same symbol.
context_after:         if let ty::ClauseKind::UnstableFeature(sym) = pred.kind().skip_binder() {