syntax_data: {"ast_node_type":"variable","tokens":[{"end":67,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:             let span = tcx.sess.source_map().guess_head_span(span);
context_before:             let span = tcx.hir_span(id);
context_after:             Some(UnsafeNotInheritedNote { span })