using System;

using System.Linq;

using System.Collections.Generic;

using System.Collections;

​

​

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Serialization;

​

    public class Employee

    {

        public string name { get; set; }

        public string lastname { get; set; }

        public int age { get; set; }

        public string someMoreDataThatShouldNotBeSerialized { get; set; }

    }

​

    public class EmployeeContainer

    {

        public IEnumerable<Employee> Employees { get; set; }

    }

​

    public class TestClass

    {

        public static IEnumerable<EmployeeContainer> GetAllEmployeeContainers()

        {

            return new[] { 

                new EmployeeContainer { 

                    Employees = 

                        new[] { 

                            new Employee { name = "John", lastname = "Coleman", age = 42, someMoreDataThatShouldNotBeSerialized = "someMoreData1" },

                            new Employee { name = "Chip", lastname = "Dale", age = 26, someMoreDataThatShouldNotBeSerialized = "someMoreData2" },

                        } 

                },

                new EmployeeContainer { 

                    Employees = 

                        new[] { 

                            new Employee { name = "Ann", lastname = "Smith", age = 33, someMoreDataThatShouldNotBeSerialized = "someMoreData3" },

                            new Employee { name = "Terry", lastname = "Johnson", age = 24, someMoreDataThatShouldNotBeSerialized = "someMoreData4" }, 

                        } 

                },

                new EmployeeContainer()

            };

        }

​

        public static void Test()

        {

            var X = GetAllEmployeeContainers();

​

            var employees = X.SelectMany(s => s.Employees ?? Enumerable.Empty<Employee>()).Select(e => new { name = e.name, lastname = e.lastname, age = e.age });

            var json = JsonConvert.SerializeObject(employees, Formatting.Indented);

            Console.WriteLine(json);

        }

    }           

​

    public class Program

    {

        public static void Main()

        {

            TestClass.Test();

        }

    }