error message 3

11-15 01:15:20.194 20591-20591/com.test.api.api E/AndroidRuntime: FATAL EXCEPTION: main
                                                                  Process: com.test.api.api, PID: 20591
                                                                  java.lang.NullPointerException: Attempt to invoke virtual method 'java.util.List com.test.api.api.GetSet.tblAkunDatabase_GET.getListtblAkun()' on a null object reference
                                                                      at com.test.api.api.Controller.Akun_Get$2.onResponse(Akun_Get.java:80)
                                                                      at retrofit2.ExecutorCallAdapterFactory$ExecutorCallbackCall$1$1.run(ExecutorCallAdapterFactory.java:70)
                                                                      at android.os.Handler.handleCallback(Handler.java:742)
                                                                      at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                      at android.os.Looper.loop(Looper.java:157)
                                                                      at android.app.ActivityThread.main(ActivityThread.java:5555)
                                                                      at java.lang.reflect.Method.invoke(Native Method)
                                                                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:745)
                                                                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:635)
                                                                      at de.robv.android.xposed.XposedBridge.main(XposedBridge.java:118)