System.Data.XSDSchema.GetParticleItems C# (CSharp) Method

        internal XmlSchemaObjectCollection GetParticleItems(XmlSchemaParticle pt)
        {
            if (pt is XmlSchemaSequence)
                return ((XmlSchemaSequence)pt).Items;
            if (pt is XmlSchemaAll)
                return ((XmlSchemaAll)pt).Items;
            if (pt is XmlSchemaChoice)
                return ((XmlSchemaChoice)pt).Items;
            if (pt is XmlSchemaAny)
                return null;
            // the code below is a little hack for the SOM behavior        
            if (pt is XmlSchemaElement)
            {
                XmlSchemaObjectCollection Items = new XmlSchemaObjectCollection();
                Items.Add(pt);
                return Items;
            }
            if (pt is XmlSchemaGroupRef)
                return GetParticleItems(((XmlSchemaGroupRef)pt).Particle);
            // should never get here.
            return null;
        }