missing fieldsecurity class

Author: Mpdreamz

src/Nest/XPack/Security/Role/FieldSecurity.cs

@@ -0,0 +1,40 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Newtonsoft.Json;
+
+namespace Nest
+{
+	[JsonConverter(typeof(ReadAsTypeJsonConverter<FieldSecurity>))]
+	public interface IFieldSecurity
+	{
+		[JsonProperty("grant")]
+		Fields Grant { get; set; }
+
+		[JsonProperty("except")]
+		Fields Except { get; set; }
+	}
+	public class FieldSecurity : IFieldSecurity
+	{
+		public Fields Grant { get; set; }
+		public Fields Except { get; set; }
+	}
+
+	public class FieldSecurityDescriptor<T>: DescriptorBase<FieldSecurityDescriptor<T>, IFieldSecurity>, IFieldSecurity
+		where T :class
+	{
+		Fields IFieldSecurity.Grant { get; set; }
+		Fields IFieldSecurity.Except { get; set; }
+
+		public FieldSecurityDescriptor<T> Grant(Func<FieldsDescriptor<T>, IPromise<Fields>> fields) =>
+			Assign(a => a.Grant = fields?.Invoke(new FieldsDescriptor<T>())?.Value);
+
+		public FieldSecurityDescriptor<T> Grant(Fields fields) => Assign(a => a.Grant = fields);
+
+		public FieldSecurityDescriptor<T> Except(Func<FieldsDescriptor<T>, IPromise<Fields>> fields) =>
+			Assign(a => a.Except = fields?.Invoke(new FieldsDescriptor<T>())?.Value);
+
+		public FieldSecurityDescriptor<T> Except(Fields fields) => Assign(a => a.Except = fields);
+
+	}
+}