System.Xml.Xsl.XmlQueryTypeFactory.SequenceType.Create C# (CSharp) Method

            public static XmlQueryType Create(XmlQueryType prime, XmlQueryCardinality card) {
                Debug.Assert(prime != null, "SequenceType can only modify the cardinality of a non-null XmlQueryType.");
                Debug.Assert(prime.IsSingleton, "Prime type must have cardinality one.");

                if (prime.TypeCode == XmlTypeCode.None) {
                    // If cardinality includes zero, then return (None, Zero), else return (None, None).
                    return XmlQueryCardinality.Zero <= card ? Zero : None;
                }

                // Normalize sequences with these cardinalities: None, Zero, One

                if (card == XmlQueryCardinality.None) {
                    return None;
                }
                else if (card == XmlQueryCardinality.Zero) {
                    return Zero;
                }
                else if (card == XmlQueryCardinality.One) {
                    return prime;
                }

                return new SequenceType(prime, card);
            }