System.Xml.XsdValidatingReader.AddAttributePSVI C# (CSharp) Method

        private AttributePSVIInfo AddAttributePSVI(int attIndex)
        {
            Debug.Assert(attIndex <= _attributePSVINodes.Length);
            AttributePSVIInfo attInfo = _attributePSVINodes[attIndex];
            if (attInfo != null)
            {
                attInfo.Reset();
                return attInfo;
            }
            if (attIndex >= _attributePSVINodes.Length - 1)
            { //reached capacity of PSVIInfo array, Need to increase capacity to twice the initial
                AttributePSVIInfo[] newPSVINodes = new AttributePSVIInfo[_attributePSVINodes.Length * 2];
                Array.Copy(_attributePSVINodes, 0, newPSVINodes, 0, _attributePSVINodes.Length);
                _attributePSVINodes = newPSVINodes;
            }
            attInfo = _attributePSVINodes[attIndex];
            if (attInfo == null)
            {
                attInfo = new AttributePSVIInfo();
                _attributePSVINodes[attIndex] = attInfo;
            }
            return attInfo;
        }