BluetoothMacProvider { public String provideBluetoothMac(BluetoothAdapter mBluetoothAdapter) { if (mBluetoothAdapter == null) { return null; }else { return mBluetoothAdapter.getAddress(); } }  BluetoothAdapter provideBluetoothDefaultAdapter(); String provideBluetoothMac(BluetoothAdapter mBluetoothAdapter);  }
@Test public void testProvideBluetoothMacNotSupported() throws Exception { BluetoothMacProvider bluetoothMacProvider = new BluetoothMacProvider(); String bluetoothMac = bluetoothMacProvider.provideBluetoothMac(null); assertNull(bluetoothMac); }