I am very new to android dev. I've watched a few youtube video's and read some documentation. Today is like day 5, so be patient with me. I am trying to build a BluetoothLE app. I stole some code from [here](http://www.truiton.com/2015/04/android-bluetooth-low-energy-ble-example/), but when I try to run in on my device. I get a "Unfortunately, (app name) has stopped" message. After commenting out different blocks of code I have pinned it down to the declaration of:

```
private ScanCallback mScanCallback = new ScanCallback() {};

```

If I include that line, it crashes. If I don't, then it lives. Here is the full Java Class:

```
package com.tremor.creech.bluetoothExample;

import android.annotation.TargetApi;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothGatt;
import android.bluetooth.le.BluetoothLeScanner;
import android.bluetooth.le.ScanCallback;
import android.bluetooth.le.ScanFilter;
import android.bluetooth.le.ScanSettings;
import android.os.Bundle;
import android.os.Handler;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;

import java.util.List;
@TargetApi(21)
public class MainActivity extends AppCompatActivity {

    private BluetoothAdapter mBluetoothAdapter;
    private int REQUEST_ENABLE_BT = 1;
    private Handler mHandler;
    private static final long SCAN_PERIOD = 10000;
    private BluetoothLeScanner mLEScanner;
    private ScanSettings settings;
    private List<ScanFilter> filters;
    private BluetoothGatt mGatt;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    private ScanCallback mScanCallback = new ScanCallback() { }; //If I include this line, then it crashes. If I take it out, then I see my Hello World activity.
}

```

LogCat errors:

```
09-15 19:16:17.503    1878-1878/com.roberts.croberts.mantis E/dalvikvm﹕ Could not find class 'com.roberts.croberts.mantis.MainActivity$1', referenced from method com.roberts.croberts.mantis.MainActivity.<init>
09-15 19:16:17.523    1878-1878/com.roberts.croberts.mantis E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.roberts.croberts.mantis, PID: 1878
    java.lang.NoClassDefFoundError: com.roberts.croberts.mantis.MainActivity$1
            at com.roberts.croberts.mantis.MainActivity.<init>(MainActivity.java:154)
            at java.lang.Class.newInstanceImpl(Native Method)
            at java.lang.Class.newInstance(Class.java:1208)
            at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2119)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2252)
            at android.app.ActivityThread.access$800(ActivityThread.java:139)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1200)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:136)
            at android.app.ActivityThread.main(ActivityThread.java:5103)
            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:790)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:606)
            at dalvik.system.NativeStart.main(Native Method)
09-15 19:16:18.023      461-717/? E/Diag_Lib﹕ Thread state: conn_id=0, state=RX_THREAD_WAIT_READ
09-15 19:16:18.023      461-717/? E/Diag_Lib﹕ Thread state: conn_id=0, state=RX_THREAD_CLIENT_TX
09-15 19:16:18.023      461-717/? E/Diag_Lib﹕ qmi_qmux: TX/RX - RX 30 bytes on conn_id=0
09-15 19:16:18.023      461-717/? E/Diag_Lib﹕ 01 1D 00 80 03 01 04 00 00 51 00 11 00 10 03 00
09-15 19:16:18.023      461-717/? E/Diag_Lib﹕ BA 0E 00 11 08 00 BE 08 00 07 00 00 00 00
09-15 19:16:18.023      461-717/? E/Diag_Lib﹕ qmuxd: TX message on fd=29, to qmux_client_id=2, len=64
09-15 19:16:18.023      461-717/? E/Diag_Lib﹕ Thread state: conn_id=0, state=RX_THREAD_WAIT_POLL
09-15 19:16:18.033      454-454/? E/Parcel﹕ Reading a NULL string not supported here.
09-15 19:16:18.033      454-454/? E/Parcel﹕ Reading a NULL string not supported here.
09-15 19:16:18.033      454-454/? E/Parcel﹕ Reading a NULL string not supported here.
09-15 19:16:18.033      454-454/? E/Parcel﹕ Reading a NULL string not supported here.

```