public MultiTenancyMiddleware(RequestDelegate next, MultiTenancyMiddlewareOptions options)
 {
     _next    = next;
     _options = options;
 }
 public static void UseMultiTenancy(this IApplicationBuilder appBuilder, MultiTenancyMiddlewareOptions options)
 {
     appBuilder.UseMiddleware <MultiTenancyMiddleware>(options);
 }