syntax_data: {"ast_node_type":"other","tokens":[{"end":72,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// a `ParamEnv` may be explicitly constructed with inference types.
context_before:     /// certain cases (currently only librustdoc's blanket impl finder),
context_after:     /// When this is the case, we do *not* want to cache the resulting selection