System.Xml.Xsl.XmlQueryTypeFactory.AddAttributes C# (CSharp) Method

        private XmlQueryCardinality AddAttributes(List<XmlQueryType> list, XmlSchemaObjectTable attributeUses, XmlSchemaAnyAttribute attributeWildcard, XmlQueryType filter) {
            XmlQueryCardinality card = XmlQueryCardinality.Zero;
            if (attributeWildcard != null) {
                XmlSchemaType attributeSchemaType = attributeWildcard.ProcessContentsCorrect == XmlSchemaContentProcessing.Skip ? DatatypeImplementation.UntypedAtomicType : DatatypeImplementation.AnySimpleType;

                // wildcard will match more then one attribute
                switch (attributeWildcard.NamespaceList.Type) {
                case NamespaceList.ListType.Set:
                    foreach (string ns in attributeWildcard.NamespaceList.Enumerate) {
                        card += AddFilteredPrime(list, CreateAttributeType(ns, false, attributeSchemaType), filter);
                    }
                    break;
                case NamespaceList.ListType.Other:
                    card += AddFilteredPrime(list, CreateAttributeType(attributeWildcard.NamespaceList.Excluded, true, attributeSchemaType), filter);
                    break;
                case NamespaceList.ListType.Any:
                default:
                    card +=  AddFilteredPrime(list, attributeWildcard.ProcessContentsCorrect == XmlSchemaContentProcessing.Skip ? UntypedAttribute : Attribute, filter);
                    break;
                }
                // Always optional
                card *= XmlQueryCardinality.ZeroOrOne;
            }
            foreach (XmlSchemaAttribute attribute in attributeUses.Values) {
                XmlQueryCardinality cardAttr = AddFilteredPrime(list, CreateAttributeType(attribute), filter);
                if (cardAttr != XmlQueryCardinality.Zero) {
                    Debug.Assert(cardAttr == XmlQueryCardinality.ZeroOrOne || cardAttr == XmlQueryCardinality.One);
                    card += (attribute.Use == XmlSchemaUse.Optional ? XmlQueryCardinality.ZeroOrOne : cardAttr);
                }
            }
            return card;
        }