Testing properties set in the mount method

I have a component which I use the mount method to assign a default value to a property from a configuration file if the property is not supplied as a parameter.

<livewire:my-component />

class MyComponent extends Component
{
  public $property = false;

  public function mount($property = null)
  {
    $trhis->property = $property ?? config('property');
  }
}

What I want to do is test that if $property is provided as an argument, then its value is assigned to $this->property otherwise, the value from the config is used.

Is there a way to test the value of $property that is provided to the mount method?

For example:

// value of $property in mount for this would be null
<livewire:my-component />

// value of $property in mount for this would be true
<livewire:my-component :property="true" />

What I would like to be able to do is assert that for the first example the value of $property is null and then that the value of $this->property is the same as config.

Then in another test be able to assert that the value of $property is not null and that its value is assigned to $this->property.