Flutter built value snippet

{
    "Built Value": {
        "prefix": "blt",
        "body": [
            "abstract class ${1} implements Built<${1}, ${1}Builder> {",
            "\t${0:// fields go here}",
            "",
            "\t${1}._();",
            "",
            "\tfactory ${1}([updates(${1}Builder b)]) = _$${1};",
            "}"
        ],
        "description": "Built Value Class"
    },
    "Built Value Serializable": {
        "prefix": "blts",
        "body": [
            "abstract class ${1} implements Built<${1}, ${1}Builder> {",
            "\t${0:// fields go here}",
            "",
            "\t${1}._();",
            "",
            "\tfactory ${1}([updates(${1}Builder b)]) = _$${1};",
            "",
            "\tString toJson() {",
            "\t\treturn json.encode(serializers.serializeWith(${1}.serializer, this));",
            "\t}",
            "",
            "\tstatic ${1} fromJson(String jsonString) {",
            "\t\treturn serializers.deserializeWith(${1}.serializer, json.decode(jsonString));",
            "\t}",
            "",
            "\tstatic Serializer<${1}> get serializer => _$${1/(^[A-z]{1})/${1:/downcase}/}Serializer;",
            "}"
        ],
        "description": "Serializable Built Value Class"
    },
    "Built Value Header": {
        "prefix": "blth",
        "body": [
            "library ${1};",
            "",
            "import 'dart:convert';",
            "",
            "import 'package:built_collection/built_collection.dart';",
            "import 'package:built_value/built_value.dart';",
            "import 'package:built_value/serializer.dart';",
            "",
            "part '${1}.g.dart';",
        ],
        "description": "Built Value Imports and File Header"
    },
}