问Json异常类型错误

EN

String sig = PortalConfig.getSignature(method, callId, params);
String url = PortalConfig.getUrl(method, callId, sig, params);  
String plainResponse = BaseClientCommunicator.executeGetMethod(url);
GsonBuilder builder = new GsonBuilder();
Gson gsonObject = builder.create();
response = gsonObject.fromJson(plainResponse, GetMenuResponse.class);
return response;

{
 "group": 
   [
     {
      "id": "206896",
      "name": "Ryż",
      "info": "xyz"
     },
     {
      "id": "206897",
      "name": "Buraki",
      "info": {}
     }
   ]
}

Exception in thread "main" com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected a string but was BEGIN_OBJECT at line 1 column 16151

public class GetMenuResponse 
{
@SerializedName("group")
private group[] group;

//method get and set
//to string method
}

public class group
{
@SerializedName("id")
private String id;
@SerializedName("name")
private String name;
@SerializedName("info")
private String info;

//method get and set
//to string method
}