[Demonstration 1]

[Buggy Method]
public void add(Task t) throws BusinessException, SystemException {
    // First, we make sure that the task DNE. Else throw BusinessException
    int taskId = 0;
    while (taskDNE(taskId)) taskId++;
    Task newTask = new Task(taskId);
    newTask.clone(t);
    taskMap.put(newTask.getId(), newTask);
}

[Buggy Hunk]
while(taskDNE(taskId))

[Patch]
while(!taskIdDNE(taskId))

[Demonstration 2]

[Buggy Method]
public boolean isValidTaskId(int updateTaskId) {
    boolean isValid = true;
    if (updateTaskId >= displayList.size() || updateTaskId < displayList.size()) {
        isValid = false;
    }
    return isValid;
}

[Buggy Hunk]
if(updateTaskId >= displayList.size() || updateTaskId < displayList.size()){

[Patch]
if(updateTaskId >= displayList.size() || updateTaskId < Constants.EMPTY_LIST_SIZE){

[Demonstration 3]

[Buggy Method]
private void createNewUser() {
    final String name = mNameEditText.getText().toString().trim();
    final String email = mEmailEditText.getText().toString().trim();
    String password = mPasswordEditText.getText().toString().trim();
    String confirmPassword = mConfirmPasswordEditText.getText().toString().trim();
    mName = mNameEditText.getText().toString().trim();
    //calling methods when the user is being created
    boolean validEmail = isValidEmail(email);
    boolean validName = isValidName(mName);
    boolean validPassword = isValidPassword(password, confirmPassword);
    if (!validEmail || !validName || validPassword)
        return;
    mAuthProgressDialog.show();
    mAuth.createUserWithEmailAndPassword(email, password).addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {

        @Override
        public void onComplete(@NonNull Task<AuthResult> task) {
            mAuthProgressDialog.dismiss();
            if (task.isSuccessful()) {
                Toast.makeText(CreateAccountActivity.this, "Authentication Successful.", Toast.LENGTH_SHORT).show();
                createFirebaseUserProfile(task.getResult().getUser());
            } else {
                Toast.makeText(CreateAccountActivity.this, "Authentication failed.", Toast.LENGTH_SHORT).show();
            }
        }
    });
}

[Buggy Hunk]
if (!validEmail || ! validName || validPassword) return;

[Patch]
if (!validEmail || ! validName || !validPassword) return;