System.Data.Common.DataColumnMappingCollection.ValidateSourceColumn C# (CSharp) Method

        internal void ValidateSourceColumn(int index, string value)
        {
            int pindex = IndexOf(value);
            if ((-1 != pindex) && (index != pindex))
            { // must be non-null and unique
                throw ADP.ColumnsUniqueSourceColumn(value);
            }
        }