WiP

app/ValueObjects/Amount.php

@@ -37,8 +37,9 @@ class Amount {
         |> function (string $value) : string { return str_replace('.', ',', $value); };
     }
 
-    public function addAmount(Amount $amount) : void {
+    public function addAmount(Amount $amount) : Amount {
         $this->amount += $amount->getAmount();
+        return $this;
     }
 
     public function subtractAmount(Amount $amount) : void {