syntax_data: {"ast_node_type":"variable","tokens":[{"end":67,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let arg = Rvalue::Use(Operand::Move(Place::from(CTX_ARG)));
context_before:             Place::from(body.local_decls.push(LocalDecl::new(context_mut_ref, source_info.span)));
context_after:         body[bb].statements.push(Statement::new(