diff --git a/CoreIntegrationTests/Infrastructure/MongoDbTKeyDocumentTestBase.cs b/CoreIntegrationTests/Infrastructure/MongoDbTKeyDocumentTestBase.cs
index a6e38d3..feb2d10 100644
--- a/CoreIntegrationTests/Infrastructure/MongoDbTKeyDocumentTestBase.cs
+++ b/CoreIntegrationTests/Infrastructure/MongoDbTKeyDocumentTestBase.cs
@@ -1127,6 +1127,91 @@ namespace CoreIntegrationTests.Infrastructure
 
         #endregion Math
 
+        #region Group By
+
+        [Fact]
+        public void GroupByTProjection()
+        {
+            // Arrange
+            var documents = CreateTestDocuments(5);
+            var content = GetContent();
+            for (var i = 0; i < documents.Count - 2; i++)
+            {
+                documents[i].GroupingKey = 1;
+                documents[i].SomeContent = $"{content}-{i}";
+            }
+            for (var i = 3; i < documents.Count; i++)
+            {
+                documents[i].GroupingKey = 2;
+                documents[i].SomeContent = $"{content}-{i}";
+            }
+            SUT.AddMany<T, TKey>(documents);
+
+            // Act
+            var result = SUT.GroupBy<T, int, ProjectedGroup, TKey>(
+                            e => e.GroupingKey, g => new ProjectedGroup
+                            {
+                                Key = g.Key,
+                                Content = g.Select(doc => doc.SomeContent).ToList()
+                            },
+                            PartitionKey);
+
+            // Assert
+            var key1Group = result.First(e => e.Key == 1);
+            Assert.NotNull(key1Group);
+            Assert.Equal(3, key1Group.Content.Count);
+            var key2Group = result.First(e => e.Key == 2);
+            Assert.NotNull(key2Group);
+            Assert.Equal(2, key2Group.Content.Count);
+        }
+
+        [Fact]
+        public void FilteredGroupByTProjection()
+        {
+            // Arrange
+            var documents = CreateTestDocuments(5);
+            var content = GetContent();
+            for (var i = 0; i < documents.Count - 2; i++)
+            {
+                documents[i].GroupingKey = 4;
+                documents[i].SomeContent = $"{content}-{i}";
+            }
+            for (var i = 3; i < documents.Count; i++)
+            {
+                documents[i].GroupingKey = 5;
+                documents[i].SomeContent = $"{content}-{i}";
+            }
+            var guid1 = Guid.NewGuid().ToString("n");
+            var guid2 = Guid.NewGuid().ToString("n");
+            for (var i = 0; i < documents.Count - 1; i++)
+            {
+                documents[i].Children = new List<Child> {
+                    new Child(guid1, guid2)
+                };
+            }
+
+            SUT.AddMany<T, TKey>(documents);
+
+            // Act
+            var result = SUT.GroupBy<T, int, ProjectedGroup, TKey>(
+                            e => e.Children.Any(c => c.Type == guid1),
+                            e => e.GroupingKey, g => new ProjectedGroup
+                            {
+                                Key = g.Key,
+                                Content = g.Select(doc => doc.SomeContent).ToList()
+                            }, PartitionKey);
+
+            // Assert
+            var key1Group = result.First(e => e.Key == 4);
+            Assert.NotNull(key1Group);
+            Assert.Equal(3, key1Group.Content.Count);
+            var key2Group = result.First(e => e.Key == 5);
+            Assert.NotNull(key2Group);
+            Assert.Single(key2Group.Content);
+        }
+
+        #endregion Group By
+
         #region Test Utils
 
         [MethodImpl(MethodImplOptions.NoInlining)]
diff --git a/CoreIntegrationTests/Infrastructure/MongoDbTestFixture.cs b/CoreIntegrationTests/Infrastructure/MongoDbTestFixture.cs
index 1b28bb1..bc360a8 100644
--- a/CoreIntegrationTests/Infrastructure/MongoDbTestFixture.cs
+++ b/CoreIntegrationTests/Infrastructure/MongoDbTestFixture.cs
@@ -27,10 +27,9 @@ namespace CoreIntegrationTests.Infrastructure
 
         public virtual void Dispose()
         {
-            var docIds = DocsToDelete.ToList().Select(e => e.Id);
-            if (docIds.Any())
+            if (DocsToDelete.Any())
             {
-                TestRepository.Instance.DeleteMany<T, TKey>(e => docIds.Contains(e.Id));
+                TestRepository.Instance.DeleteMany<T, TKey>(DocsToDelete.ToList());
             }
         }
 
@@ -46,8 +45,9 @@ namespace CoreIntegrationTests.Infrastructure
             var docs = new List<T>();
             for (var i = 0; i < numberOfDocumentsToCreate; i++)
             {
-                docs.Add(new T());
-                DocsToDelete.Add(docs.Last());
+                var doc = new T();
+                docs.Add(doc);
+                DocsToDelete.Add(doc);
             }
             return docs;
         }
diff --git a/CoreIntegrationTests/Infrastructure/TestClasses.cs b/CoreIntegrationTests/Infrastructure/TestClasses.cs
index c9ad2b9..13d02d4 100644
--- a/CoreIntegrationTests/Infrastructure/TestClasses.cs
+++ b/CoreIntegrationTests/Infrastructure/TestClasses.cs
@@ -82,6 +82,7 @@ namespace CoreIntegrationTests.Infrastructure
             Children = new List<Child>();
         }
 
+        public int GroupingKey { get; set; }
         public string SomeContent { get; set; }
         public string SomeContent4 { get; set; }
         public string SomeContent5 { get; set; }
diff --git a/MongoDbGenericRepository/BaseMongoRepository.Main.cs b/MongoDbGenericRepository/BaseMongoRepository.Main.cs
index b7df9cc..19b9e86 100644
--- a/MongoDbGenericRepository/BaseMongoRepository.Main.cs
+++ b/MongoDbGenericRepository/BaseMongoRepository.Main.cs
@@ -3,7 +3,6 @@ using MongoDbGenericRepository.Models;
 using MongoDbGenericRepository.Utils;
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Threading.Tasks;