syntax_data: {"ast_node_type":"other","tokens":[{"end":62,"kind":"keyword","start":0,"text":"if"}]}
source_snippet:                 if self.serialized_ctxts.lock().insert(ctxt) {
context_before:             for (ctxt, ctxt_key) in all_ctxt_data {
context_after:                     encode_ctxt(encoder, ctxt.0, &ctxt_key);