skeeks\cms\models\User::findByUsernameOrEmail PHP Method

    public static function findByUsernameOrEmail($value)
    {
        if ($user = static::findByUsername($value)) {
            return $user;
        }
        if ($user = static::findByEmail($value)) {
            return $user;
        }
        return null;
    }

 /**
  * Finds user by [[username]]
  *
  * @return User|null
  */
 public function getUser()
 {
     if ($this->_user === false) {
         $this->_user = User::findByUsernameOrEmail($this->identifier);
     }
     return $this->_user;
 }