improve readability of MessageParsingHelpers
diff --git a/csharp/src/Google.Protobuf.Test/MessageParsingHelpers.cs b/csharp/src/Google.Protobuf.Test/MessageParsingHelpers.cs
index 95b426d..05f1e36 100644
--- a/csharp/src/Google.Protobuf.Test/MessageParsingHelpers.cs
+++ b/csharp/src/Google.Protobuf.Test/MessageParsingHelpers.cs
@@ -41,38 +41,38 @@
     {
         public static void AssertReadingMessage<T>(MessageParser<T> parser, byte[] bytes, Action<T> assert) where T : IMessage<T>
         {
-            var parsedBuffer = parser.ParseFrom(bytes);
-            assert(parsedBuffer);
+            var parsedMsg = parser.ParseFrom(bytes);
+            assert(parsedMsg);
 
             // Load content as single segment
-            parsedBuffer = parser.ParseFrom(new ReadOnlySequence<byte>(bytes));
-            assert(parsedBuffer);
+            parsedMsg = parser.ParseFrom(new ReadOnlySequence<byte>(bytes));
+            assert(parsedMsg);
 
             // Load content as multiple segments
-            parsedBuffer = parser.ParseFrom(ReadOnlySequenceFactory.CreateWithContent(bytes));
-            assert(parsedBuffer);
+            parsedMsg = parser.ParseFrom(ReadOnlySequenceFactory.CreateWithContent(bytes));
+            assert(parsedMsg);
 
             // Load content as ReadOnlySpan
-            parsedBuffer = parser.ParseFrom(new ReadOnlySpan<byte>(bytes));
-            assert(parsedBuffer);
+            parsedMsg = parser.ParseFrom(new ReadOnlySpan<byte>(bytes));
+            assert(parsedMsg);
         }
 
         public static void AssertReadingMessage(MessageParser parser, byte[] bytes, Action<IMessage> assert)
         {
-            var parsedBuffer = parser.ParseFrom(bytes);
-            assert(parsedBuffer);
+            var parsedMsg = parser.ParseFrom(bytes);
+            assert(parsedMsg);
 
             // Load content as single segment
-            parsedBuffer = parser.ParseFrom(new ReadOnlySequence<byte>(bytes));
-            assert(parsedBuffer);
+            parsedMsg = parser.ParseFrom(new ReadOnlySequence<byte>(bytes));
+            assert(parsedMsg);
 
             // Load content as multiple segments
-            parsedBuffer = parser.ParseFrom(ReadOnlySequenceFactory.CreateWithContent(bytes));
-            assert(parsedBuffer);
+            parsedMsg = parser.ParseFrom(ReadOnlySequenceFactory.CreateWithContent(bytes));
+            assert(parsedMsg);
 
             // Load content as ReadOnlySpan
-            parsedBuffer = parser.ParseFrom(new ReadOnlySpan<byte>(bytes));
-            assert(parsedBuffer);
+            parsedMsg = parser.ParseFrom(new ReadOnlySpan<byte>(bytes));
+            assert(parsedMsg);
         }
 
         public static void AssertReadingMessageThrows<TMessage, TException>(MessageParser<TMessage> parser, byte[] bytes)
@@ -95,24 +95,24 @@
             message.WriteTo(bufferWriter);
             Assert.AreEqual(bytes, bufferWriter.WrittenSpan.ToArray(), "Both serialization approaches need to result in the same data.");
 
-            var parsedBuffer = parser.ParseFrom(bytes);
-            Assert.AreEqual(message, parsedBuffer);
-            additionalAssert?.Invoke(parsedBuffer);
+            var parsedMsg = parser.ParseFrom(bytes);
+            Assert.AreEqual(message, parsedMsg);
+            additionalAssert?.Invoke(parsedMsg);
 
             // Load content as single segment
-            parsedBuffer = parser.ParseFrom(new ReadOnlySequence<byte>(bytes));
-            Assert.AreEqual(message, parsedBuffer);
-            additionalAssert?.Invoke(parsedBuffer);
+            parsedMsg = parser.ParseFrom(new ReadOnlySequence<byte>(bytes));
+            Assert.AreEqual(message, parsedMsg);
+            additionalAssert?.Invoke(parsedMsg);
 
             // Load content as multiple segments
-            parsedBuffer = parser.ParseFrom(ReadOnlySequenceFactory.CreateWithContent(bytes));
-            Assert.AreEqual(message, parsedBuffer);
-            additionalAssert?.Invoke(parsedBuffer);
+            parsedMsg = parser.ParseFrom(ReadOnlySequenceFactory.CreateWithContent(bytes));
+            Assert.AreEqual(message, parsedMsg);
+            additionalAssert?.Invoke(parsedMsg);
 
             // Load content as ReadOnlySpan
-            parsedBuffer = parser.ParseFrom(new ReadOnlySpan<byte>(bytes));
-            Assert.AreEqual(message, parsedBuffer);
-            additionalAssert?.Invoke(parsedBuffer);
+            parsedMsg = parser.ParseFrom(new ReadOnlySpan<byte>(bytes));
+            Assert.AreEqual(message, parsedMsg);
+            additionalAssert?.Invoke(parsedMsg);
         }
 
         public static void AssertWritingMessage(IMessage message)