syntax_data: {"ast_node_type":"other","tokens":[{"end":80,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         //   The instantiation from the input trait-ref is therefore going to be
context_before:         //   where both `'x` and `'b` would have a DB index of 1.
context_after:         //   `'a => 'x` (where `'x` has a DB index of 1).