syntax_data: {"ast_node_type":"function","tokens":[{"end":62,"kind":"keyword","start":0,"text":"pub"}]}
source_snippet:     pub fn is_desugaring(self, kind: DesugaringKind) -> bool {
context_before:     /// Checks if this span arises from a compiler desugaring of kind `kind`.
context_after:         match self.ctxt().outer_expn_data().kind {