using System;

using System.Linq;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var options1 = new GuiControlOptionsModel(

            new Dictionary<string, object>

            {

                {"key1", "value1"},

                {"key2", "value2"},

                {"key3", "value3"},

                {"key4", "value4"},

                {"key5", "value5"},

            }

        );

        var options2 = new GuiControlOptionsModel(

            new Dictionary<string, object>

            {

                {"key2", "value2-from2"},

                {"key4", "value4-from2"},

            }

        );

​

        var mergedOptions = MergeLayoutControlOptions(

            options1,

            options2

        );

​

        foreach (var option in mergedOptions)

        {

            System.Console.WriteLine(

                $"Key: {option.Key} | Value: {option.Value}"

            );

        }

    }

​

    private static GuiControlOptionsModel MergeLayoutControlOptions(

        params IGuiControlOptions[] options

    )

    {

        return new GuiControlOptionsModel(

            options.SelectMany(x => x)

                .GroupBy(d => d.Key)

                .ToDictionary(x => x.Key, y => y.Last().Value)

        );

    }

​

    public interface IGuiControlOptions

        : IDictionary<string, object>

    {

​

    }

​

    public class GuiControlOptionsModel

        : Dictionary<string, object>,

        IGuiControlOptions

    {

        public GuiControlOptionsModel(

            IDictionary<string, object> dictionary

        ) : base(dictionary ?? new Dictionary<string, object>())

        {

        }

    }

}