CSHARP-1221: Removed unnecessary argument null check.

Author: craiggwilson

src/MongoDB.Driver.Tests/IAggregateFluentExtensionsTests.cs

@@ -42,7 +42,7 @@ public void Group_should_generate_the_correct_group_when_a_result_type_is_not_sp
         public void Group_should_generate_the_correct_document_using_expressions()
         {
             var subject = CreateSubject()
-                .Group(x => x.Age, g =>  new { Name = g.Select(x => x.FirstName + " " + x.LastName).First() });
+                .Group(x => x.Age, g => new { Name = g.Select(x => x.FirstName + " " + x.LastName).First() });
 
             var expectedGroup = BsonDocument.Parse("{$group: {_id: '$Age', Name: {'$first': { '$concat': ['$FirstName', ' ', '$LastName']}}}}");
 
@@ -176,6 +176,17 @@ public void Unwind_with_expression_to_BsonDocument_should_generate_the_correct_u
             AssertLast(subject, expectedUnwind);
         }
 
+        [Test]
+        public void Unwind_with_expression_to_new_result_should_generate_the_correct_unwind()
+        {
+            var subject = CreateSubject()
+                .Unwind<Person, BsonDocument>(x => x.Age);
+
+            var expectedUnwind = BsonDocument.Parse("{$unwind: '$Age'}");
+
+            AssertLast(subject, expectedUnwind);
+        }
+
         [Test]
         public void Unwind_should_generate_the_correct_unwind()
         {
@@ -188,7 +199,7 @@ public void Unwind_should_generate_the_correct_unwind()
         }
 
         [Test]
-        public void Unwind_with_expression_to_new_result_should_generate_the_correct_unwind()
+        public void Unwind_to_new_result_with_a_serializer_should_generate_the_correct_unwind()
         {
             var subject = CreateSubject()
                 .Unwind("Age", BsonDocumentSerializer.Instance);

src/MongoDB.Driver/IAggregateFluentExtensions.cs

@@ -267,7 +267,6 @@ public static IAggregateFluent<TNewResult> Unwind<TResult, TNewResult>(this IAgg
         {
             Ensure.IsNotNull(aggregate, "aggregate");
             Ensure.IsNotNull(field, "field");
-            Ensure.IsNotNull(newResultSerializer, "newResultSerializer");
 
             return aggregate.Unwind<TNewResult>(new ExpressionFieldDefinition<TResult>(field), newResultSerializer);
         }