Backendless PHP调用非对象上的成员函数

I have been trying to retrieve data from backendless database using PHP but i get this error. I followed the documentation but there is no much details written.

Below is my code

<?php
require_once('Plant.php');
use backendless\Backendless;
include "vendor/backendless/autoload.php";
Backendless::initApp('API-KEY', 'API-KEY', 'v1');
$first_contact = Backendless::$Persistence->of('Plant')->findFirst();
$first_contact->getName();


<?php
class Plant {
private $userId;
private $tempLimit;
private $name;
private $lightLimit;
private $lastWatered;
private $humidityLimit;
private $currentTemp;
private $currentHumidity;
private $currentLight;
public function __construct() {
}
public function getName() {
return $thsi->name;
}
public function setName( $name ) {
$this->name = $name;
}
public function getUserId() {
return $thsi->userId;
}
public function setUserId( $userId ) {
$this->userId = $userId;
}
public function gettempLimit() {
return $thsi->tempLimit;
}
public function setTempLimit( $tempLimit ) {
$this->tempLimit = $tempLimit;
}
public function getLightLimit() {
return $thsi->lightLimit;
}
public function setLightLimit( $lightLimit ) {
$this->lightLimit = $lightLimit;
}
public function getLastWatered() {
return $thsi->lastWatered;
}
public function setLastWatered( $lastWatered ) {
$this->lastWatered = $lastWatered;
}
public function getHumidityLimit() {
return $thsi->humidityLimit;
}
public function setHumidityLimit( $humidityLimit ) {
$this->humidityLimit = $humidityLimit;
}
public function getCurrentTemp() {
return $thsi->currentTemp;
}
public function setCurrentTemp( $currentTemp ) {
$this->currentTemp = $currentTemp;
}
}