System.Collections.Specialized.OrderedDictionary.this C# (CSharp) Method

        public object this[int index]
        {
            get
            {
                return ((DictionaryEntry)objectsArray[index]).Value;
            }
            set
            {
                if (_readOnly)
                {
                    throw new NotSupportedException(SR.OrderedDictionary_ReadOnly);
                }
                if (index < 0 || index >= objectsArray.Count)
                {
                    throw new ArgumentOutOfRangeException(nameof(index));
                }
                object key = ((DictionaryEntry)objectsArray[index]).Key;
                objectsArray[index] = new DictionaryEntry(key, value);
                objectsTable[key] = value;
            }
        }