class Ingredient
{
    public string Name { get; set; }
    public int Calories { get; set; }
}

Butter
Milk
Suger

Ingredient[] ingredients =
{
    new Ingredient {Name = "Suger", Calories = 500},
    new Ingredient {Name = "Egg", Calories = 100},
    new Ingredient {Name = "Milk", Calories = 150},
    new Ingredient {Name = "Flour", Calories = 50},
    new Ingredient {Name = "Butter", Calories = 200}
};

IEnumerable<string> highCalories =
    from i in ingredients
    where i.Calories >= 150
    orderby i.Name
    select i.Name;

foreach (var item in highCalories)
{
    Console.WriteLine(item);
}

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <package id="Microsoft.AspNet.OData" version="6.0.0" targetFramework="net462" />
  <package id="Microsoft.AspNet.SignalR.Core" version="2.2.1" targetFramework="net462" />
  <package id="Microsoft.AspNet.SignalR.Owin" version="1.2.2" targetFramework="net462" />
  <package id="Microsoft.AspNet.WebApi.Client" version="5.2.3" targetFramework="net462" />
  <package id="Microsoft.AspNet.WebApi.Core" version="5.2.3" targetFramework="net462" />
  <package id="Microsoft.AspNet.WebApi.Owin" version="5.2.3" targetFramework="net462" />
  <package id="Microsoft.CodeDom.Providers.DotNetCompilerPlatform" version="1.0.2" targetFramework="net462" />
  <package id="Microsoft.Extensions.DependencyInjection" version="1.0.0" targetFramework="net462" />
  <package id="Microsoft.Extensions.DependencyInjection.Abstractions" version="1.0.0" targetFramework="net462" />
  <package id="Microsoft.Net.Compilers" version="1.3.2" targetFramework="net462" developmentDependency="true" />
  <package id="Microsoft.OData.Core" version="7.0.0" targetFramework="net462" />
  <package id="Microsoft.OData.Edm" version="7.0.0" targetFramework="net462" />
  <package id="Microsoft.Owin" version="3.0.1" targetFramework="net462" />
  <package id="Microsoft.Owin.FileSystems" version="3.0.1" targetFramework="net462" />
  <package id="Microsoft.Owin.Host.SystemWeb" version="3.0.1" targetFramework="net462" />
  <package id="Microsoft.Owin.Security" version="3.0.1" targetFramework="net462" />
  <package id="Microsoft.Owin.StaticFiles" version="3.0.1" targetFramework="net462" />
  <package id="Microsoft.Spatial" version="7.0.0" targetFramework="net462" />
  <package id="Newtonsoft.Json" version="9.0.1" targetFramework="net462" />
  <package id="Owin" version="1.0" targetFramework="net462" />
  <package id="System.Collections" version="4.0.11" targetFramework="net462" />
  <package id="System.Collections.Concurrent" version="4.0.12" targetFramework="net462" />
  <package id="System.ComponentModel" version="4.0.1" targetFramework="net462" />
  <package id="System.Diagnostics.Debug" version="4.0.11" targetFramework="net462" />
  <package id="System.Globalization" version="4.0.11" targetFramework="net462" />
  <package id="System.Linq" version="4.1.0" targetFramework="net462" />
  <package id="System.Linq.Expressions" version="4.1.0" targetFramework="net462" />
  <package id="System.Reflection" version="4.1.0" targetFramework="net462" />
  <package id="System.Resources.ResourceManager" version="4.0.1" targetFramework="net462" />
  <package id="System.Runtime.Extensions" version="4.1.0" targetFramework="net462" />
  <package id="System.Threading" version="4.0.11" targetFramework="net462" />
  <package id="System.Threading.Tasks" version="4.0.11" targetFramework="net462" />
</packages>

PM>Update-Package -reinstall -Project YourProjectName

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <appSettings>
    <add key="owin:AppStartup" value="OwinKatanaTest.OwinAppStartup, OwinKatanaTest" />
    <!-- Owin App Startup Class -->
    <add key="webpages:Enabled" value="false" />
    <!-- Disable asp.net web pages. Note that based on our current configuration, asp.net web forms, mvc and web pages won't work. This configuration is for owin stuffs only, for example asp.net web api & odata, signalr, etc. -->
  </appSettings>
  <system.web>
    <compilation debug="true" defaultLanguage="c#" enablePrefetchOptimization="true" optimizeCompilations="true" targetFramework="4.6.2">
      <assemblies>
        <remove assembly="*" />
        <!-- To improve app startup performance, our app will continue its work without this compilations, these are required for asp.net web forms, mvc and web pages. -->
        <add assembly="OwinKatanaTest" />
      </assemblies>
    </compilation>
    <httpRuntime targetFramework="4.6.2" />
    <httpModules>
      <!-- No need to these modules and handlers, owin handler itself will do everything for us -->
      <clear />
    </httpModules>
    <httpHandlers>
      <clear />
    </httpHandlers>
    <sessionState mode="Off" />
  </system.web>
  <system.codedom>
    <compilers>
      <compiler language="c#;cs;csharp" extension=".cs" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.2.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:6 /nowarn:1659;1699;1701" />
    </compilers>
  </system.codedom>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="Microsoft.Owin" publicKeyToken="31bf3856ad364e35" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-9.0.0.0" newVersion="9.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Microsoft.Owin.Security" publicKeyToken="31bf3856ad364e35" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Microsoft.AspNet.SignalR.Core" publicKeyToken="31bf3856ad364e35" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-2.2.1.0" newVersion="2.2.1.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Reflection" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-4.1.0.0" newVersion="4.1.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Runtime.Extensions" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-4.1.0.0" newVersion="4.1.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Http" publicKeyToken="31bf3856ad364e35" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-5.2.3.0" newVersion="5.2.3.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Net.Http.Formatting" publicKeyToken="31bf3856ad364e35" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-5.2.3.0" newVersion="5.2.3.0" />
      </dependentAssembly>
    </assemblyBinding>
  </runtime>
  <system.webServer>
    <validation validateIntegratedModeConfiguration="false" />
    <modules runAllManagedModulesForAllRequests="false">
      <!-- We're not going to remove all modules, some modules such as static & dynamic compression modules are really cool (-: -->
      <remove name="RewriteModule" />
      <remove name="OutputCache" />
      <remove name="Session" />
      <remove name="WindowsAuthentication" />
      <remove name="FormsAuthentication" />
      <remove name="DefaultAuthentication" />
      <remove name="RoleManager" />
      <remove name="FileAuthorization" />
      <remove name="UrlAuthorization" />
      <remove name="AnonymousIdentification" />
      <remove name="Profile" />
      <remove name="UrlMappingsModule" />
      <remove name="ServiceModel-4.0" />
      <remove name="UrlRoutingModule-4.0" />
      <remove name="ScriptModule-4.0" />
      <remove name="Isapi" />
      <remove name="IsapiFilter" />
      <remove name="DigestAuthentication" />
      <remove name="WindowsAuthentication" />
      <remove name="ServerSideInclude" />
      <remove name="DirectoryListing" />
      <remove name="DefaultDocument" />
      <remove name="CustomError" />
      <remove name="Cgi" />
    </modules>
    <defaultDocument>
      <!-- Default docs will be configured using owin static files middleware -->
      <files>
        <clear />
      </files>
    </defaultDocument>
    <handlers>
      <!-- Only use this handler for all requests -->
      <clear />
      <add name="Owin" verb="*" path="*" type="Microsoft.Owin.Host.SystemWeb.OwinHttpHandler, Microsoft.Owin.Host.SystemWeb" />
    </handlers>
    <httpProtocol>
      <customHeaders>
        <clear />
      </customHeaders>
    </httpProtocol>
  </system.webServer>
</configuration>

using Microsoft.AspNet.SignalR;
using Microsoft.OData;
using Microsoft.OData.Edm;
using Owin;
using OwinKatanaTest.Model;
using OwinKatanaTest.ODataControllers;
using System.Collections.Generic;
using System.Web.Http;
using System.Web.OData.Builder;
using System.Web.OData.Extensions;
using System.Web.OData.Routing.Conventions;

namespace OwinKatanaTest
{
    public class OwinAppStartup
    {
        public void Configuration(IAppBuilder owinApp)
        {
            owinApp.Map("/odata", innerOwinAppForOData =>
            {
                HttpConfiguration webApiODataConfig = new HttpConfiguration();
                webApiODataConfig.IncludeErrorDetailPolicy = IncludeErrorDetailPolicy.Always;

                webApiODataConfig.Formatters.Clear();

                IEnumerable<IODataRoutingConvention> conventions = ODataRoutingConventions.CreateDefault();

                ODataModelBuilder modelBuilder = new ODataConventionModelBuilder(webApiODataConfig);

                modelBuilder.Namespace = modelBuilder.ContainerName = "Test";
                var categoriesSetConfig = modelBuilder.EntitySet<Category>("Categories");
                var getBestCategoryFunctionConfig = categoriesSetConfig.EntityType.Collection.Function(nameof(CategoriesController.GetBestCategory));
                getBestCategoryFunctionConfig.ReturnsFromEntitySet<Category>("Categories");

                IEdmModel edmModel = modelBuilder.GetEdmModel();

                webApiODataConfig.MapODataServiceRoute("default", "", builder =>
                {
                    builder.AddService(ServiceLifetime.Singleton, sp => conventions);
                    builder.AddService(ServiceLifetime.Singleton, sp => edmModel);
                });

                innerOwinAppForOData.UseWebApi(webApiODataConfig);

            });

            owinApp.Map("/api", innerOwinAppForWebApi =>
            {
                HttpConfiguration webApiConfig = new HttpConfiguration();
                webApiConfig.IncludeErrorDetailPolicy = IncludeErrorDetailPolicy.Always;

                webApiConfig.MapHttpAttributeRoutes();

                webApiConfig.Routes.MapHttpRoute(name: "default", routeTemplate: "{controller}/{action}", defaults: new { action = RouteParameter.Optional });

                innerOwinAppForWebApi.UseWebApi(webApiConfig);
            });

            owinApp.Map("/signalr", innerOwinAppForSignalR =>
            {
                innerOwinAppForSignalR.RunSignalR(new HubConfiguration
                {
                    EnableDetailedErrors = true
                });
            });

            owinApp.UseStaticFiles();

            owinApp.Run(async context =>
            {
                await context.Response.WriteAsync("owin katana");
            });
        }
    }
}

using OwinKatanaTest.Model;
using System.Web.Http;
using System.Web.OData;

namespace OwinKatanaTest.ODataControllers
{
    public class CategoriesController : ODataController
    {
        [HttpGet]
        public Category GetBestCategory()
        {
            return new Category { Id = 1, Name = "Test" };
        }
    }
}

using OwinKatanaTest.Model;
using System.Collections.Generic;
using System.Web.Http;

namespace OwinKatanaTest.ApiControllers
{
    public class ProductsController : ApiController
    {
        [HttpGet]
        [Route("products/{categoryId}")]
        public List<Product> GetProductsByCategoryId(int categoryId)
        {
            return new List<Product>
            {
                new Product { Id = 1 , Name = "Test" }
            };
        }
    }
}

<package id="Microsoft.Owin.Testing" version="3.0.1" targetFramework="net462" />

using Microsoft.Owin.Testing;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using OwinKatanaTest;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;

namespace Test
{
    [TestClass]
    public class Test
    {
        [TestMethod]
        public async Task TestWebApi()
        {
            using (TestServer server = TestServer.Create<OwinAppStartup>())
            {
                HttpResponseMessage apiResponse = await server.HttpClient.GetAsync("/api/products/1");
                apiResponse.EnsureSuccessStatusCode();
                Assert.AreEqual(HttpStatusCode.OK, apiResponse.StatusCode);
            }
        }

        [TestMethod]
        public async Task TestOData()
        {
            using (TestServer server = TestServer.Create<OwinAppStartup>())
            {
                HttpResponseMessage odataResponse = await server.HttpClient.GetAsync("odata/Categories/Test.GetBestCategory");
                odataResponse.EnsureSuccessStatusCode();
                Assert.AreEqual(HttpStatusCode.OK, odataResponse.StatusCode);
            }
        }
    }
}