使用下面的代码，我想将$ 2中的变量转换为小写字母，但我无法完全使它起作用。

    "Build Model": {
        "prefix": "mod","body": [
            "import '${1:../backend.dart}';","","class ${2:Class} extends ManagedObject<_$2> implements _$2 {}","${2/(*)/${2:/downcase}/}","${2:/downcase}" //would be nice to be able to do this
            "@Table(name: \"${2/(*)/${2:/downcase}/}\")","class _$2 {","@Column(primaryKey: true,autoincrement: true,indexed: true)","int id;","$3","}",""
        ],"description": "Build a data model"
    },