URIUniversalCommunication can not be multiple URI

[mconstabel]

Hello,

electronic_address: Container = MultiField(
        URIUniversalCommunication, required=False, profile=BASIC

so it seems it can store multiple URI.

if "uri" in uri_list:
    for uri in d.trade.agreement.seller.uri:
        uri_data = URIUniversalCommunication(uri_ID = ("UR", uri.get("name", "")) )
        doc.trade.agreement.seller.electronic_address.add( uri_data )

But if I use more than one URI, len(uri_list) > 1, there is an error.

URIUniversalCommunication': This element is not expected. Expected is (

According to EN 16931 URIUniversalCommunication is only one adress?