syntax_data: {"ast_node_type":"variable","tokens":[{"end":80,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                 let source_info = SourceInfo { span, scope: this.source_scope };
context_before:                     .get_or_insert_with(|| this.new_source_scope(scope_span, LintLevel::Inherited));
context_after:                 let user_tys = user_tys.build_user_type_projections();