{"ast_node_type":"variable","tokens":[{"end":65,"kind":"keyword","start":0,"text":"let"}]}
    let rhs = make::expr_path(make::ext::ident_path(field_name));
    let lhs = make::expr_field(self_expr, field_name);
    let assign_stmt = make::expr_stmt(make::expr_assignment(lhs, rhs));