syntax_data: {"ast_node_type":"other","tokens":[{"end":47,"kind":"keyword","start":0,"text":"DefKind::Closure"}]}
source_snippet:         DefKind::Closure => "closure argument",
context_before:         DefKind::AssocFn | DefKind::Fn => "function argument",
context_after:         // other types of MIR don't have function parameters, and we don't need to