SimplePublicObjectInput Not Found

[MPenn6]

Using the PHP hubspot/api-client composer package.

composer require hubspot/api-client

Most API calls have been working great, but I'm running into some issues with Line Items. I'm basing my code off of the samples from here: https://developers.hubspot.com/docs/api/crm/line-items

But I'm finding that SimplePublicObjectInput is not a defined object. I'm not seeing anybody else with this issue, so I'm guessing I am overlooking something obvious! Here's my code snippet:

use HubSpot\Factory;
use HubSpot\Client\Crm\LineItems\ApiException;

class lineitem
{
private function hs_createNewTaxLineItem()
    {
        $client = Factory::createWithApiKey(HUBSPOT_API_KEY);

       
        $properties = [
            "hs_product_id" => HS_SALES_TAX_PRODUCT_ID,
            "quantity" => "1",
            "price" => 99.98
        ];
        $SimplePublicObjectInput = new SimplePublicObjectInput(['properties' => $properties]);
        try {
            $apiResponse = $client->crm()->lineItems()->basicApi()->create($SimplePublicObjectInput);
            var_dump($apiResponse);
        } catch (ApiException $e) {
            echo "Exception when calling basic_api->create: ", $e->getMessage();
        }
}

It returns the error:

 Fatal error: Uncaught Error: Class 'SimplePublicObjectInput' not found in...

Any ideas?

[MPenn6]

Playing around with this a little more....

This does NOT work for creating the object:

$SimplePublicObjectInput = new SimplePublicObjectInput(['properties' => $properties]);

But I CAN create the object like this:

$SimplePublicObjectInput =  new \HubSpot\Client\Crm\LineItems\Model\SimplePublicObjectInput(['properties' => $properties]);

 Is this normal way to code this? 

The only other way I can access this object is if I literally specify it in the use statement

use HubSpot\Client\Crm\LineItems\Model\SimplePublicObjectInput;