Entity/Shipment.php
public function setStatus($status)
    {
        if ($status !== $this->status) {
            $this->status = $status;
            $this->setMailStep(0);
        }


        return $this;
    }
public function setStatus($status)
    {
        if ($status !== $this->status) {
            $this->status = $status;
            $this->setMailStep(0);
        }


        return $this;
    }
Set state

@param integer $status

@return Shipment