{"ast_node_type":"other","tokens":[{"end":37,"kind":"keyword","start":0,"text":"AstFragmentKind::OptExpr"}]}
        AstFragmentKind::OptExpr => {
        AstFragmentKind::MethodReceiverExpr => AstFragment::MethodReceiverExpr(this.parse_expr()?),
            if this.token != token::Eof {