using System;

​

public class Entity

{

    public string FirstName;

    public string LastName;

}

​

public class Program

{

    public static void Main()

    {

        var a = new Entity();

        var isValidEntity = GetValidEntity(a);

        if(isValidEntity)

        {

            Console.WriteLine("Is valid entity");

        }

        else

        {

            Console.WriteLine("Is in valid entity");        

        }

    }

    /// The objective for this method is validate if the entity is a valid entity

    public static bool GetValidEntity(Entity entity)

    {

        if(entity != null)

        {

            if(entity.FirstName != null)

            {

                if(entity.LastName != null)

                {

                    return true;        

                }

                else

                {

                    return false;

                }

            }

            else

            {

                return false;

            }

        }

        else

        {

            throw new ArgumentNullException();

        }

    }   

}

​

​