models/LoginForm.php
private function getUser()
	{
		if ($this->_user === false) {
			$this->_user = User::findByUsername($this->username);
		}
		return $this->_user;
	}
private function getUser()
	{
		if ($this->_user === false) {
			$this->_user = User::findByUsername($this->username);
		}
		return $this->_user;
	}
Finds user by [[username]]

@return User|null