Proguard config to use retrofit Retrofit

my app is running all ok in debug, but when creating apk to release, I'm getting the follow error.

Process: neocom.dealerbook, PID: 9044
    java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0
            at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
            at java.util.ArrayList.get(ArrayList.java:308)
            at neocom.dealerbook.controller.k.a(MapActivity.java:103)
            at neocom.dealerbook.controller.k.success(MapActivity.java:98)
            at retrofit.CallbackRunnable$1.run(CallbackRunnable.java:45)
            at android.os.Handler.handleCallback(Handler.java:733)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:136)
            at android.app.ActivityThread.main(ActivityThread.java:5086)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
            at dalvik.system.NativeStart.main(Native Method)

Here is the MapActivity.java:103

Callback<ClienteConfiguracao> callback = new Callback<ClienteConfiguracao>() {
                int failCount = 0;
            @Override
            public void success(ClienteConfiguracao clienteConfiguracao, Response response) {
                currentClient = clienteConfiguracao.getDealerships().get(0); /* Line 103 */
                setupToggles(currentClient);

                List<String> mAuthorization = clienteConfiguracao.getAuthorization();
                toAllowPermissions = new HashMap<>();
                Set<String> allImplementedKeys = PermissionManager.ALL_PERMISSIONS.keySet();
                for (String key : mAuthorization) {
                    if (allImplementedKeys.contains(key)) {
                        List value = PermissionManager.ALL_PERMISSIONS.get(key);
                        toAllowPermissions.put(key, value);
                    }
                }

Here is the proguard file that I build searching for the errors that I got, Retrofit site and others.

-assumenosideeffects class android.util.Log {
    public static boolean isLoggable(java.lang.String, int);
    public static int v(...);
    public static int i(...);
    public static int w(...);
    public static int d(...);
    public static int e(...);
}
-dontwarn retrofit.**
-dontwarn com.squareup.okhttp.**
-dontwarn okio.**
-dontwarn retrofit.appengine.UrlFetchClient
-keep class retrofit.** { *; }
-keep class com.squareup.okhttp.** { *; }
-keep interface com.squareup.okhttp.** { *; }
-keepattributes Signature
-keepattributes Exceptions
-keepattributes *Annotation*
-keepattributes SourceFile
-keepattributes LineNumberTable


-keepclasseswithmembers class * {
    @retrofit.http.* <methods>;
}

Is there any tip about it?

When using retrofit with gson is important to add the Progard rule to the classes that are serialized and deserialized .

For example:

-keep class com.example.model.** { *; }

PS: Another advice is to use the rules snippets from this repository altlink. There are rules for a lot of different libraries.