Work on VOIP and Domain products

app/Models/Product/Domain.php

@@ -2,11 +2,32 @@
 
 namespace App\Models\Product;
 
+use Illuminate\Support\Collection;
+
+use App\Interfaces\ProductSupplier;
+use App\Models\Base\ProductType;
 use App\Traits\NextKey;
 
-class Domain extends \App\Models\Base\ProductType
+class Domain extends ProductType implements ProductSupplier
 {
 	use NextKey;
-
 	const RECORD_ID = '';
+
+	public function allowance(): Collection
+	{
+		// N/A
+		return collect();
+	}
+
+	public function allowance_string(): string
+	{
+		// N/A
+		return '';
+	}
+
+	public function getCostAttribute(): float
+	{
+		// N/A
+		return 0;
+	}
 }