Add Cat Health test where Timestamp is false

_cat/health also supports ts=0 - elastic/elasticsearch#13508, but it's sufficient to only support the true/false form

Author: russcam

src/Tests/Cat/CatHealth/CatHealthApiTests.cs

@@ -1,4 +1,5 @@
-using Elasticsearch.Net;
+using System;
+using Elasticsearch.Net;
 using FluentAssertions;
 using Nest;
 using Tests.Framework;
@@ -29,4 +30,39 @@ protected override void ExpectResponse(ICatResponse<CatHealthRecord> response)
 		}
 	}
 
+	[Collection(TypeOfCluster.ReadOnly)]
+	public class CatHealthNoTimestampApiTests : ApiIntegrationTestBase<ICatResponse<CatHealthRecord>, ICatHealthRequest, CatHealthDescriptor, CatHealthRequest>
+	{
+		public CatHealthNoTimestampApiTests(ReadOnlyCluster cluster, EndpointUsage usage) : base(cluster, usage) { }
+		protected override LazyResponses ClientUsage() => Calls(
+			fluent: (client, f) => client.CatHealth(f),
+			fluentAsync: (client, f) => client.CatHealthAsync(f),
+			request: (client, r) => client.CatHealth(r),
+			requestAsync: (client, r) => client.CatHealthAsync(r)
+		);
+
+		protected override bool ExpectIsValid => true;
+		protected override int ExpectStatusCode => 200;
+		protected override HttpMethod HttpMethod => HttpMethod.GET;
+		protected override string UrlPath => "/_cat/health?ts=false";
+
+		protected override Func<CatHealthDescriptor, ICatHealthRequest> Fluent => s => s
+			.Ts(false);
+
+		protected override CatHealthRequest Initializer => new CatHealthRequest
+		{
+			Ts = false
+		};
+
+		protected override void ExpectResponse(ICatResponse<CatHealthRecord> response)
+		{
+			response.Records.Should().NotBeEmpty().And.Contain(a => !string.IsNullOrEmpty(a.Status));
+
+			foreach (var record in response.Records)
+			{
+				record.Timestamp.Should().BeNullOrWhiteSpace();
+			}
+		}
+	}
+
 }