[Demonstration 1]

[Buggy Method]
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    modelItems = new ArrayList<newUser>();
    emailInputText = (EditText) findViewById(R.id.email_input_Text);
    passwordInputText = (EditText) findViewById(R.id.password_input_text);
    usernameInputText = (EditText) findViewById(R.id.username_input_text);
    loginBtn = (Button) findViewById(R.id.login_button);
    loginBtn.setEnabled(false);
    mDatabase = FirebaseDatabase.getInstance().getReference();
    mDatabase = mDatabase.getRoot().child("Users");
    mAuth = FirebaseAuth.getInstance();
    mAuthListener = new FirebaseAuth.AuthStateListener() {

        @Override
        public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
            FirebaseUser user = firebaseAuth.getCurrentUser();
            if (user != null) {
                // User is signed in
                Log.d("onAuthStateChanged", "onAuthStateChanged:signed_in:" + user.getUid());
            } else {
                // User is signed out
                Log.d("onAuthStateChanged", "onAuthStateChanged:signed_out");
            }
        }
    };
    mDatabase.addValueEventListener(new ValueEventListener() {

        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            for (DataSnapshot postSnapshot : dataSnapshot.getChildren()) {
                newUser post = postSnapshot.getValue(newUser.class);
                modelItems.add(new newUser(post.getName(), post.getEmail(), post.getLocation(), post.getPermission()));
                System.out.println("DONE");
                loginBtn.setEnabled(true);
            }
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {
        }
    });
}

[Buggy Hunk]
modelItems.add(new newUser(post.getName(),post.getEmail(),post.getLocation(),post.getPermission()));

[Patch]
modelItems.add(new newUser(post.getName(),post.getEmail(),postSnapshot.getKey(),post.getPermission()));

[Demonstration 2]

[Buggy Method]
@Override
public void setAdapter(ListAdapter adapter) {
    final WrapAdapter mAdapter = new WrapAdapter(adapter);
    adapter.registerDataSetObserver(new DataSetObserver() {

        @Override
        public void onChanged() {
            super.onChanged();
            post(new Runnable() {

                @Override
                public void run() {
                    mAdapter.notifyDataSetChanged();
                }
            });
        }

        @Override
        public void onInvalidated() {
            super.onInvalidated();
            post(new Runnable() {

                @Override
                public void run() {
                    mAdapter.notifyDataSetInvalidated();
                }
            });
        }
    });
    super.setAdapter(mAdapter);
}

[Buggy Hunk]
final WrapAdapter mAdapter = new WrapAdapter(adapter);

[Patch]
mAdapter = new WrapAdapter(adapter);

[Demonstration 3]

[Buggy Method]
public static Result service(String ownerName, String projectName, String service, boolean isAdvertise) throws IOException, UnsupportedOperationException, ServletException {
    if (!isSupportedService(service)) {
        return forbidden(String.format("Unsupported service: '%s'", service));
    }
    Project project = Project.findByOwnerAndProjectName(ownerName, projectName);
    if (project == null) {
        return notFound();
    }
    models.User user = UserApp.currentUser();
    if (!isAllowed(project, service)) {
        if (user.isAnonymous()) {
            return BasicAuthAction.unauthorized(response());
        } else {
            // If you want the Git client showing your custom message to
            // the user, the Content-Type should be exact "text/plain"
            // without any parameter. For more details, see the code at
            // https://github.com/git/git/commit/426e70d4a11ce3b4f70636d57c6a0ab16ae08a00#diff-eea0ad565ec5903a11b6023755d491cfR154
            response().setHeader("Content-Type", "text/plain");
            return forbidden(String.format("'%s' has no permission to '%s/%s'.", user.name, ownerName, projectName));
        }
    }
    if (isAdvertise) {
        return ok(RepositoryService.gitAdvertise(project, service, response()));
    } else {
        if (request().body().isMaxSizeExceeded()) {
            return status(REQUEST_ENTITY_TOO_LARGE);
        } else {
            user.visits(project);
            return ok(RepositoryService.gitRpc(project, service, request(), response()));
        }
    }
}

[Buggy Hunk]
user.name, ownerName, projectName));

[Patch]
user.loginId, ownerName, projectName));