Code in documentation not working

Content

Using the code below, I get an error:

Message: Invalid argument supplied for foreach()

Also when I try to use:

$contact = RNCPHP\Contact::first("Login = '".$agent."'");
print_r($contact);

It prints it out but at no point can I get any values to show. Doing a var_dump shows NULL values as well

What's happening?

Version

Version info Oracle Service Cloud 18A (Build 260 SP 3, CP 322)

Code Snippet

             $contact = RNCPHP\Contact::find("Name.Last = 'Smith'");
foreach ($contacts as $contact) {
	print($contact->ID);
}