code: public function user($key = null) {
  		if ($this->sessionKey && $this->request->session()->check($this->sessionKey)) {
  			$user = $this->request->session()->read($this->sessionKey);
  		} else {
  			return null;
  		}
  		if ($key === null) {
  			return $user;
  		}
  		return Hash::get($user, $key);
  	}
docs: Accessor to the logged in user's properties
  
  @param string $key Key to read
  @return mixed