syntax_data: {"ast_node_type":"other","tokens":[{"end":78,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                 // return ambiguity. Otherwise, if exactly one matches, equate
context_before:                 // any match. If not, error. Then, if *more* than one matches, we
context_after:                 // it with b_ty's projection.