syntax_data: {"ast_node_type":"other","tokens":[{"end":79,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// If the self type is an alias type, e.g. an opaque type or a projection,
context_before:     ParamEnv(ParamEnvSource),
context_after:     /// we know the bounds on that alias to hold even without knowing its concrete