Remove breaking change

Author: gliljas

src/NHibernate/Async/Id/Enhanced/SequenceStructure.cs

@@ -26,7 +26,7 @@ public partial class SequenceStructure : IDatabaseStructure
 
 		#region Nested type: SequenceAccessCallback
 
-		private partial class SequenceAccessCallback : IAccessCallback
+		private partial class SequenceAccessCallback : IMultiTenantAccessCallback
 		{
 
 			#region IAccessCallback Members

src/NHibernate/Async/Id/Enhanced/TableGenerator.cs

@@ -34,7 +34,7 @@ public virtual async Task<object> GenerateAsync(ISessionImplementor session, obj
 			}
 		}
 
-		private partial class TableAccessCallback : IAccessCallback
+		private partial class TableAccessCallback : IMultiTenantAccessCallback
 		{
 
 			#region IAccessCallback Members

src/NHibernate/Async/Id/Enhanced/TableStructure.cs

@@ -95,7 +95,7 @@ public override async Task<object> DoWorkInCurrentTransactionAsync(ISessionImple
 
 		#region Nested type: TableAccessCallback
 
-		private partial class TableAccessCallback : IAccessCallback
+		private partial class TableAccessCallback : IMultiTenantAccessCallback
 		{
 
 			#region IAccessCallback Members

src/NHibernate/Id/Enhanced/IAccessCallback.cs

@@ -10,10 +10,18 @@ public partial interface IAccessCallback
 		/// Retrieve the next value from the underlying source.
 		/// </summary>
 		long GetNextValue();
+	}
 
+	internal interface IMultiTenantAccessCallback : IAccessCallback
+	{
 		/// <summary>
 		/// Obtain the tenant identifier (multi-tenancy), if one, associated with this callback.
 		/// </summary>
 		string GetTenantIdentifier();
 	}
+
+	internal static class AccessCallbackExtensions
+	{
+		internal static string GetTenantIdentifier(this IAccessCallback accessCallback) => (accessCallback as IMultiTenantAccessCallback)?.GetTenantIdentifier();
+	}
 }

src/NHibernate/Id/Enhanced/SequenceStructure.cs

@@ -80,7 +80,7 @@ public int TimesAccessed
 
 		#region Nested type: SequenceAccessCallback
 
-		private partial class SequenceAccessCallback : IAccessCallback
+		private partial class SequenceAccessCallback : IMultiTenantAccessCallback
 		{
 			private readonly SequenceStructure _owner;
 			private readonly ISessionImplementor _session;

src/NHibernate/Id/Enhanced/TableGenerator.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Data;
 using System.Data.Common;
@@ -385,7 +385,7 @@ public virtual object Generate(ISessionImplementor session, object obj)
 			}
 		}
 
-		private partial class TableAccessCallback : IAccessCallback
+		private partial class TableAccessCallback : IMultiTenantAccessCallback
 		{
 			private TableGenerator _owner;
 			private readonly ISessionImplementor _session;

src/NHibernate/Id/Enhanced/TableStructure.cs

@@ -163,7 +163,7 @@ public override object DoWorkInCurrentTransaction(ISessionImplementor session, D
 
 		#region Nested type: TableAccessCallback
 
-		private partial class TableAccessCallback : IAccessCallback
+		private partial class TableAccessCallback : IMultiTenantAccessCallback
 		{
 			private readonly TableStructure _owner;
 			private readonly ISessionImplementor _session;