syntax_data: {"ast_node_type":"impl","tokens":[{"end":62,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:     //    is `Vec<Foo>: Iterable<Bar>`, but the impl specifies
context_before:     //    those specified by the impl/bound. For example, if the obligation
context_after:     //    `impl<T> Iterable<T> for Vec<T>`, than an error would result.