add checks and code fixes.

modules/cms-kit/src/Volo.CmsKit.Domain/Volo/CmsKit/Contents/Content.cs

@@ -8,41 +8,37 @@ namespace Volo.CmsKit.Contents
 {
     public class Content : FullAuditedAggregateRoot<Guid>, IMultiTenant
     {
-        [CanBeNull]
-        public virtual Guid? TenantId { get; protected set; }
-        
-        [NotNull]
-        public virtual string EntityType { get; protected set; }
-        
-        [NotNull]
-        public virtual string EntityId { get; protected set; }
-        
-        [NotNull]
-        public virtual string Value { get; protected set; }
+        [CanBeNull] public virtual Guid? TenantId { get; protected set; }
+
+        [NotNull] public virtual string EntityType { get; protected set; }
+
+        [NotNull] public virtual string EntityId { get; protected set; }
+
+        [NotNull] public virtual string Value { get; protected set; }
 
         protected Content()
         {
-            
         }
-        
-        public Content(Guid id, [NotNull] string entityType, [NotNull] string entityId, [NotNull] string value, Guid? tenantId = null) : base(id)
+
+        public Content(Guid id, [NotNull] string entityType, [NotNull] string entityId, [NotNull] string value,
+            Guid? tenantId = null) : base(id)
         {
             EntityId = Check.NotNullOrWhiteSpace(entityId, nameof(entityId), ContentConsts.MaxEntityIdLength);
             EntityType = Check.NotNullOrEmpty(entityType, nameof(entityType), ContentConsts.MaxEntityTypeLength);
             Value = Check.NotNullOrEmpty(value, nameof(value), ContentConsts.MaxValueLength);
-            
+
             TenantId = tenantId;
         }
 
-        public void SetValue([NotNull] string value)
+        public virtual void SetValue([NotNull] string value)
         {
             Value = Check.NotNullOrEmpty(value, nameof(value), ContentConsts.MaxValueLength);
         }
 
-        public void SetEntity([NotNull] string entityType, [NotNull] string entityId)
+        public virtual void SetEntity([NotNull] string entityType, [NotNull] string entityId)
         {
             EntityType = Check.NotNullOrEmpty(entityType, nameof(entityType), ContentConsts.MaxEntityTypeLength);
             EntityId = Check.NotNullOrWhiteSpace(entityId, nameof(entityId), ContentConsts.MaxEntityIdLength);
         }
     }
-}
+}

modules/cms-kit/src/Volo.CmsKit.Domain/Volo/CmsKit/Pages/Page.cs

@@ -8,7 +8,7 @@ namespace Volo.CmsKit.Pages
 {
     public class Page : FullAuditedAggregateRoot<Guid>, IMultiTenant
     {
-        [CanBeNull] public virtual Guid? TenantId { get; set; }
+        [CanBeNull] public virtual Guid? TenantId { get; protected set; }
 
         [NotNull] public virtual string Title { get; protected set; }
 

modules/cms-kit/src/Volo.CmsKit.Domain/Volo/CmsKit/Tags/Tag.cs

@@ -8,7 +8,7 @@ namespace Volo.CmsKit.Tags
 {
     public class Tag : FullAuditedAggregateRoot<Guid>, IMultiTenant
     {
-        public virtual Guid? TenantId { get; set; }
+        public virtual Guid? TenantId { get; protected set; }
 
         [NotNull]
         public virtual string EntityType { get; protected set; }
@@ -33,7 +33,7 @@ namespace Volo.CmsKit.Tags
 
         public virtual void SetName(string name)
         {
-            Name = Check.NotNullOrWhiteSpace(name, nameof(name), TagConsts.MaxNameLength);
+            Name = Check.NotNullOrEmpty(name, nameof(name), TagConsts.MaxNameLength);
         }
 
         public virtual void SetEntityType(string entityType)