lib/Model/Address.php
public function setFirstName($first_name)
    {
        if (!is_null($first_name) && (strlen($first_name) > 200)) {
            throw new \InvalidArgumentException('invalid length for $first_name when calling Address., must be smaller than or equal to 200.');
        }

        $this->container['first_name'] = $first_name;

        return $this;
    }
public function setFirstName($first_name)
    {
        if (!is_null($first_name) && (strlen($first_name) > 200)) {
            throw new \InvalidArgumentException('invalid length for $first_name when calling Address., must be smaller than or equal to 200.');
        }

        $this->container['first_name'] = $first_name;

        return $this;
    }
Sets first_name
@param string $first_name The recipient's first name
@return $this