syntax_data: {"ast_node_type":"impl","tokens":[{"end":65,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // reason is similar to the previous example: any impl of
context_before:         // The answer is that we know `for<'x,'b> T: Bar1<'x,'b>`. The
context_after:         // `T:Foo1<'x>` must show that `for<'b> T: Bar1<'x, 'b>`. So