syntax_data: {"ast_node_type":"other","tokens":[{"end":81,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// An assumption from the environment. Stores a [`ParamEnvSource`], since we
context_before:     BuiltinImpl(BuiltinImplSource),
context_after:     /// prefer non-global param-env candidates in candidate assembly.