change the readonly property as =>

src/Microsoft.OpenApi.OData.Reader/Edm/ODataPath.cs

@@ -52,7 +52,7 @@ namespace Microsoft.OpenApi.OData.Edm
         /// <summary>
         /// Gets the path kind.
         /// </summary>
-        public ODataPathKind Kind
+        public virtual ODataPathKind Kind
         {
             get
             {

src/Microsoft.OpenApi.OData.Reader/PathItem/EntityPathItemHandler.cs

@@ -15,7 +15,7 @@ namespace Microsoft.OpenApi.OData.PathItem
     internal class EntityPathItemHandler : EntitySetPathItemHandler
     {
         /// <inheritdoc/>
-        protected override ODataPathKind HandleKind { get; } = ODataPathKind.Entity;
+        protected override ODataPathKind HandleKind => ODataPathKind.Entity;
 
         /// <inheritdoc/>
         protected override void SetOperations(OpenApiPathItem item)

src/Microsoft.OpenApi.OData.Reader/PathItem/EntitySetPathItemHandler.cs

@@ -16,7 +16,7 @@ namespace Microsoft.OpenApi.OData.PathItem
     internal class EntitySetPathItemHandler : PathItemHandler
     {
         /// <inheritdoc/>
-        protected override ODataPathKind HandleKind { get; } = ODataPathKind.EntitySet;
+        protected override ODataPathKind HandleKind => ODataPathKind.EntitySet;
 
         /// <summary>
         /// Gets the entity set.

src/Microsoft.OpenApi.OData.Reader/PathItem/NavigationPropertyPathItemHandler.cs

@@ -22,7 +22,7 @@ namespace Microsoft.OpenApi.OData.PathItem
     internal class NavigationPropertyPathItemHandler : PathItemHandler
     {
         /// <inheritdoc/>
-        protected override ODataPathKind HandleKind { get; } = ODataPathKind.NavigationProperty;
+        protected override ODataPathKind HandleKind => ODataPathKind.NavigationProperty;
 
         /// <summary>
         /// Gets the navigation property.

src/Microsoft.OpenApi.OData.Reader/PathItem/OperationImportPathItemHandler.cs

@@ -15,7 +15,7 @@ namespace Microsoft.OpenApi.OData.PathItem
     internal class OperationImportPathItemHandler : PathItemHandler
     {
         /// <inheritdoc/>
-        protected override ODataPathKind HandleKind { get; } = ODataPathKind.OperationImport;
+        protected override ODataPathKind HandleKind => ODataPathKind.OperationImport;
 
         /// <summary>
         /// Gets the operation import.

src/Microsoft.OpenApi.OData.Reader/PathItem/OperationPathItemHandler.cs

@@ -19,7 +19,7 @@ namespace Microsoft.OpenApi.OData.PathItem
     internal class OperationPathItemHandler : PathItemHandler
     {
         /// <inheritdoc/>
-        protected override ODataPathKind HandleKind { get; } = ODataPathKind.Operation;
+        protected override ODataPathKind HandleKind => ODataPathKind.Operation;
 
         /// <summary>
         /// Gets the Edm operation.

src/Microsoft.OpenApi.OData.Reader/PathItem/PathItemHandlerProvider.cs

@@ -15,7 +15,7 @@ namespace Microsoft.OpenApi.OData.PathItem
     {
         private IDictionary<ODataPathKind, IPathItemHandler> _handlers = new Dictionary<ODataPathKind, IPathItemHandler>
         {
-            // Entity
+            // EntitySet
             { ODataPathKind.EntitySet, new EntitySetPathItemHandler() },
 
             // Entity

src/Microsoft.OpenApi.OData.Reader/PathItem/SingletonPathItemHandler.cs

@@ -16,7 +16,7 @@ namespace Microsoft.OpenApi.OData.PathItem
     internal class SingletonPathItemHandler : PathItemHandler
     {
         /// <inheritdoc/>
-        protected override ODataPathKind HandleKind { get; } = ODataPathKind.Singleton;
+        protected override ODataPathKind HandleKind => ODataPathKind.Singleton;
 
         /// <summary>
         /// Gets the singleton.

test/Microsoft.OpenAPI.OData.Reader.Tests/PathItem/PathItemHandlerProviderTests.cs

@@ -18,6 +18,7 @@ namespace Microsoft.OpenApi.OData.PathItem.Tests
         [InlineData(ODataPathKind.NavigationProperty, typeof(NavigationPropertyPathItemHandler))]
         [InlineData(ODataPathKind.Operation, typeof(OperationPathItemHandler))]
         [InlineData(ODataPathKind.OperationImport, typeof(OperationImportPathItemHandler))]
+        [InlineData(ODataPathKind.Unknown, null)]
         public void GetHandlerReturnsCorrectHandlerType(ODataPathKind pathKind, Type handlerType)
         {
             // Arrange