[Demonstration 1]

[Buggy Method]
@Override
public void remoteDeviceRemoved(Registry registry, RemoteDevice device) {
    super.remoteDeviceRemoved(registry, device);
    listener.onDeviceDiscovered(new RemoteDeviceImpl(device));
}

[Buggy Hunk]
listener.onDeviceDiscovered(new RemoteDeviceImpl(device));

[Patch]
listener.onDeviceLeave(new RemoteDeviceImpl(device));

[Demonstration 2]

[Buggy Method]
@Override
public void handleLoad(Activity context, final ActionButton<A> button) {
    final OnActionButtonEventListener<A> listener = button.getOnActionButtonEventListener();
    Entity entity = button.getEntity();
    if (entity != null) {
        button.setState(ActionButtonState.LOADING);
        handleLoad(context, entity, new OnActionButtonEventListener<A>() {

            @Override
            public void onLoad(Activity context, A action, Entity entity) {
                button.setEntity(entity);
                handleAfterLoad(context, button, action);
                if (listener != null) {
                    listener.onLoad(context, action, entity);
                }
            }

            @Override
            public boolean onBeforeAction(Activity context) {
                return true;
            }

            @Override
            public void onAfterAction(Activity context, SocializeAction action, Entity entity) {
            }

            @Override
            public void onError(Activity context, Exception e) {
                button.setState(ActionButtonState.DISABLED);
                if (logger != null) {
                    logger.error("Failed to load action button", e);
                }
                if (listener != null) {
                    listener.onError(context, e);
                }
            }
        });
    } else {
        handleNoEntityError(context, button, listener);
    }
}

[Buggy Hunk]
button.setState(ActionButtonState.DISABLED);

[Patch]
button.setState(ActionButtonState.FAILED);

[Demonstration 3]

[Buggy Method]
@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
    Toast.makeText(UserActivity.this, "Connection failed", Toast.LENGTH_SHORT).show();
}

[Buggy Hunk]
Toast.makeText(UserActivity.this, "Connection failed", Toast.LENGTH_SHORT).show();

[Patch]
Toast.makeText(getApplicationContext(), R.string.connection_failed, Toast.LENGTH_SHORT).show();