Add product checks

Author: stevejgordon

src/Elasticsearch.Net/Transport/Pipeline/IRequestPipeline.cs

@@ -15,12 +15,10 @@ public interface IRequestPipeline : IDisposable
 		bool FirstPoolUsageNeedsSniffing { get; }
 		bool IsTakingTooLong { get; }
 		int MaxRetries { get; }
-
 		int Retried { get; }
 		bool SniffsOnConnectionFailure { get; }
 		bool SniffsOnStaleCluster { get; }
 		bool StaleClusterState { get; }
-
 		DateTime StartedOn { get; }
 
 		TResponse CallElasticsearch<TResponse>(RequestData requestData)

src/Elasticsearch.Net/Transport/Pipeline/PipelineException.cs

@@ -6,6 +6,16 @@
 
 namespace Elasticsearch.Net
 {
+	public class InvalidProductException : Exception
+	{
+		public InvalidProductException()
+			: base(@"TODO: This client is designed to work with the official Elasticsearch product...
+
+Why are you seeing this error?
+------------------------------
+TODO") { }
+	}
+
 	public class PipelineException : Exception
 	{
 		public PipelineException(PipelineFailure failure)
@@ -18,9 +28,7 @@ public PipelineException(PipelineFailure failure, Exception innerException)
 		public PipelineFailure FailureReason { get; }
 
 		public bool Recoverable =>
-			FailureReason == PipelineFailure.BadRequest
-			|| FailureReason == PipelineFailure.BadResponse
-			|| FailureReason == PipelineFailure.PingFailure;
+			FailureReason is PipelineFailure.BadRequest or PipelineFailure.BadResponse or PipelineFailure.PingFailure;
 
 		public IElasticsearchResponse Response { get; internal set; }
 

src/Elasticsearch.Net/Transport/Pipeline/ProductCheckStatus.cs

@@ -0,0 +1,17 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+namespace Elasticsearch.Net
+{
+	/// <summary>
+	/// Represents the status of the pre-flight product checks.
+	/// </summary>
+	public enum ProductCheckStatus
+	{
+		NotChecked,
+		ValidProduct,
+		InvalidProduct,
+		UndeterminedProduct
+	}
+}