AutoMapper： Mapper.Initialize() 只能调用一次，Why？

最开始的代码

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using System.Reflection;

 using AutoMapper;

 using Happy.ExtentionMethods;
 using Happy.Bootstrap;

 namespace Happy.Bootstrap.AutoMapper
 {
     /// <summary>
     /// 自动添加配置。
     /// </summary>
     public class AutoAddProfilePlugin : IBootstrapPlugin
     {
         /// <inheritdoc />
         public void Start(IBootstrapService bootstrapService, Assembly assembly)
         {
             bootstrapService.MustNotNull("bootstrapService");
             assembly.MustNotNull("assembly");

             foreach (var type in assembly.GetTypes())
             {
                 if (type.IsAbstract || type.IsInterface)
                 {
                     continue;
                 }

                 if (typeof(Profile).IsAssignableFrom(type))
                 {
                     Mapper.Initialize(x => {
                         x.AddProfile(Activator.CreateInstance(type) as Profile);
                     });
                 }
             }
         }
     }
 }

问题

我的项目中，每个 dll 都是自描述的，系统启动的时候，对每个 dll 对执行上面的插件，结果， Mapper.Initialize() 只有最后一次配置才有效，前面的配置会丢失。

最后的代码

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using System.Reflection;

 using AutoMapper;

 using Happy.ExtentionMethods;
 using Happy.Bootstrap;

 namespace Happy.Bootstrap.AutoMapper
 {
     /// <summary>
     /// 自动添加配置。
     /// </summary>
     public class AutoAddProfilePlugin : IBootstrapPlugin
     {
         /// <inheritdoc />
         public void Start(IBootstrapService bootstrapService, Assembly assembly)
         {
             bootstrapService.MustNotNull("bootstrapService");
             assembly.MustNotNull("assembly");

             foreach (var type in assembly.GetTypes())
             {
                 if (type.IsAbstract || type.IsInterface)
                 {
                     continue;
                 }

                 if (typeof(Profile).IsAssignableFrom(type))
                 {
                     Mapper.AddProfile(Activator.CreateInstance(type) as Profile);
                 }
             }
         }
     }
 }