Remove repeated item_ids

Author: sergioteula

amazon_paapi/helpers/arguments.py

@@ -18,9 +18,9 @@ def get_items_ids(items: Union[str, List[str]]) -> List[str]:
         items_ids = [get_asin(x.strip()) for x in items]
 
     if items_ids:
-        return items_ids
-    else:
-        raise AsinNotFoundException('No ASIN codes have been found.')
+        return list(set(items_ids))
+
+    raise AsinNotFoundException('No ASIN codes have been found.')
 
 
 def check_search_args(**kwargs):