/**
  * @param $username
  * @return bool
  */
 public function addAction($username)
 {
     $user = User::findFirst([['username' => $username]]);
     if ($user) {
         return $this->succeed(['message' => 'User already exists.']);
     }
     $user = new User();
     $user->username = $username;
     if ($user->save()) {
         return $this->succeed();
     } else {
         return $this->fail(['message' => 'Error saving to Database.']);
     }
 }
 /**
  * @param $username
  * @return bool
  */
 public function listAction($username)
 {
     // Get User
     /** @var User $user */
     $user = User::findFirst([['username' => $username]]);
     if (!$user) {
         return $this->fail(['message' => "User doesn't exist."]);
     }
     return $this->succeed($user->getNewsSourcesInfo());
 }