diff --git a/src/PinkParrot.Infrastructure.Tests/PropertiesBagTests.cs b/src/PinkParrot.Infrastructure.Tests/PropertiesBagTests.cs
index 221791b01..0a0ef6567 100644
--- a/src/PinkParrot.Infrastructure.Tests/PropertiesBagTests.cs
+++ b/src/PinkParrot.Infrastructure.Tests/PropertiesBagTests.cs
@@ -30,6 +30,19 @@ namespace PinkParrot.Infrastructure
             dynamicBag = bag;
         }
 
+        [Fact]
+        public void Should_serialize_and_deserialize_empty()
+        {
+            var serializerSettings = new JsonSerializerSettings();
+
+            serializerSettings.Converters.Add(new PropertiesBagConverter());
+
+            var content = JsonConvert.SerializeObject(bag, serializerSettings);
+            var response = JsonConvert.DeserializeObject<PropertiesBag>(content, serializerSettings);
+            
+            Assert.Equal(bag.Count, response.Count);
+        }
+
         [Fact]
         public void Should_serialize_and_deserialize()
         {
@@ -312,6 +325,14 @@ namespace PinkParrot.Infrastructure
             AssertString("Foo");
         }
 
+        [Fact]
+        public void Should_provide_null()
+        {
+            bag.Set("Key", null);
+
+            AssertNull();
+        }
+
         [Fact]
         public void Should_throw_when_converting_instant_to_number()
         {
@@ -335,6 +356,12 @@ namespace PinkParrot.Infrastructure
             Assert.Equal(expected, (string)dynamicBag.Key);
         }
 
+        private void AssertNull()
+        {
+            Assert.Null(bag["Key"].ToString());
+            Assert.Null(bag["Key"].RawValue);
+        }
+
         private void AssertBoolean(bool expected)
         {
             Assert.Equal(expected, bag["Key"].ToBoolean(c));
diff --git a/src/PinkParrot.Infrastructure.Tests/TypeNameRegistryTests.cs b/src/PinkParrot.Infrastructure.Tests/TypeNameRegistryTests.cs
index 0bb361784..dec1e6499 100644
--- a/src/PinkParrot.Infrastructure.Tests/TypeNameRegistryTests.cs
+++ b/src/PinkParrot.Infrastructure.Tests/TypeNameRegistryTests.cs
@@ -1,8 +1,13 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
+// ==========================================================================
+//  TypeNameRegistryTests.cs
+//  PinkParrot Headless CMS
+// ==========================================================================
+//  Copyright (c) PinkParrot Group
+//  All rights reserved.
+// ==========================================================================
+
+using System;
 using System.Reflection;
-using System.Threading.Tasks;
 using Xunit;
 
 namespace PinkParrot.Infrastructure
diff --git a/src/PinkParrot.Infrastructure/Guard.cs b/src/PinkParrot.Infrastructure/Guard.cs
index fb5cca769..b5aefcda7 100644
--- a/src/PinkParrot.Infrastructure/Guard.cs
+++ b/src/PinkParrot.Infrastructure/Guard.cs
@@ -9,7 +9,6 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
-using System.Globalization;
 using System.IO;
 using System.Linq;
 using System.Runtime.CompilerServices;
diff --git a/src/PinkParrot.Infrastructure/Reflection/PropertiesTypeAccessor.cs b/src/PinkParrot.Infrastructure/Reflection/PropertiesTypeAccessor.cs
index 3e8794ddb..aa8dcfd32 100644
--- a/src/PinkParrot.Infrastructure/Reflection/PropertiesTypeAccessor.cs
+++ b/src/PinkParrot.Infrastructure/Reflection/PropertiesTypeAccessor.cs
@@ -9,7 +9,6 @@
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 
 namespace PinkParrot.Infrastructure.Reflection
diff --git a/src/pinkparrot_infrastructure/PinkParrot.Infrastructure.Tests/CQRS/EnvelopeExtensionsTest.cs b/src/pinkparrot_infrastructure/PinkParrot.Infrastructure.Tests/CQRS/EnvelopeExtensionsTest.cs
new file mode 100644
index 000000000..05a650182
--- /dev/null
+++ b/src/pinkparrot_infrastructure/PinkParrot.Infrastructure.Tests/CQRS/EnvelopeExtensionsTest.cs
@@ -0,0 +1,75 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using NodaTime;
+using NuGet.Versioning;
+using Xunit;
+
+namespace PinkParrot.Infrastructure.CQRS
+{
+    public class EnvelopeExtensionsTest
+    {
+        private readonly Envelope<object> envelope = new Envelope<object>(1, new EnvelopeHeaders());
+
+        [Fact]
+        public void Should_set_and_get_timestamp()
+        {
+            var timestamp = SystemClock.Instance.GetCurrentInstant();
+
+            envelope.SetTimestamp(timestamp);
+
+            Assert.Equal(timestamp, envelope.Headers.Timestamp());
+        }
+
+        [Fact]
+        public void Should_set_and_get_event_id()
+        {
+            var eventId = Guid.NewGuid();
+
+            envelope.SetEventId(eventId);
+
+            Assert.Equal(eventId, envelope.Headers.EventId());
+        }
+
+        [Fact]
+        public void Should_set_and_get_event_number()
+        {
+            const int eventNumber = 123;
+
+            envelope.SetEventNumber(eventNumber);
+
+            Assert.Equal(eventNumber, envelope.Headers.EventNumber());
+        }
+
+        [Fact]
+        public void Should_set_and_get_aggregate_id()
+        {
+            var aggregateId = Guid.NewGuid();
+
+            envelope.SetAggregateId(aggregateId);
+
+            Assert.Equal(aggregateId, envelope.Headers.AggregateId());
+        }
+
+        [Fact]
+        public void Should_set_and_get_tenant_id()
+        {
+            var tenantId = Guid.NewGuid();
+
+            envelope.SetTenantId(tenantId);
+
+            Assert.Equal(tenantId, envelope.Headers.TenantId());
+        }
+
+        [Fact]
+        public void Should_set_and_get_commit_id()
+        {
+            var commitId = Guid.NewGuid();
+
+            envelope.SetCommitId(commitId);
+
+            Assert.Equal(commitId, envelope.Headers.CommitId());
+        }
+    }
+}