syntax_data: {"ast_node_type":"other","tokens":[{"end":99,"kind":"keyword","start":0,"text":"Some(&ExternCrate"}]}
source_snippet:                 Some(&ExternCrate { src, dependency_of, span, .. }) => match (src, dependency_of) {
context_before:             match self.tcx().extern_crate(cnum) {
context_after:                     (ExternCrateSource::Extern(def_id), LOCAL_CRATE) => {