public override void OnConfigure(
     IDescriptorContext context,
     IObjectFieldDescriptor descriptor,
     MemberInfo member)
 {
     if (_errorBuilderType != null)
     {
         descriptor.UseFluentValidation(_errorBuilderType);
     }
     else
     {
         descriptor.UseFluentValidation();
     }
 }
 /// <summary>
 /// Adds FluentValidation field middleware.
 /// It is going to validate all non-null field arguments and report errors if there is one or more failures.
 /// </summary>
 /// <typeparam name="T">Custom error builder class used to construct single validation error.</typeparam>
 public static IObjectFieldDescriptor UseFluentValidation <TErrorBuilder>(
     this IObjectFieldDescriptor descriptor) where TErrorBuilder : IValidationErrorBuilder
 {
     return(descriptor.UseFluentValidation(typeof(TErrorBuilder)));
 }
 /// <summary>
 /// Adds FluentValidation field middleware.
 /// It is going to validate all non-null field arguments and report errors if there is one or more failures.
 /// </summary>
 public static IObjectFieldDescriptor UseFluentValidation(
     this IObjectFieldDescriptor descriptor)
 {
     return(descriptor.UseFluentValidation <ValidationErrorBuilder>());
 }