diff --git a/mongodb/example/README.md b/mongodb/example/README.md
new file mode 100644
index 00000000..cd4c9e44
--- /dev/null
+++ b/mongodb/example/README.md
@@ -0,0 +1,9 @@
+# Spring Data MongoDB - Example
+
+This project contains examples for:
+
+* Derived finder and geo spatial queries using a `Repository` interface.
+* `EntityCallback` API usage for before convert/save interaction.
+* Result projections for DTOs and interface types.  
+* Query metadata. 
+
diff --git a/mongodb/example/src/main/java/example/springdata/mongodb/immutable/ApplicationConfiguration.java b/mongodb/example/src/main/java/example/springdata/mongodb/immutable/ApplicationConfiguration.java
index 10357fda..9e2c5239 100644
--- a/mongodb/example/src/main/java/example/springdata/mongodb/immutable/ApplicationConfiguration.java
+++ b/mongodb/example/src/main/java/example/springdata/mongodb/immutable/ApplicationConfiguration.java
@@ -5,7 +5,7 @@
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
- *      http://www.apache.org/licenses/LICENSE-2.0
+ *      https://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
@@ -24,16 +24,19 @@ import org.springframework.data.mongodb.core.mapping.event.BeforeConvertCallback
 import com.mongodb.MongoClient;
 
 /**
- * Test configuration to connect to a MongoDB named "test" and using a {@link MongoClient}. Also enables Spring Data
- * repositories for MongoDB.
+ * Test configuration to connect to a MongoDB named "test" using a {@link MongoClient}. <br />
+ * Also enables Spring Data repositories for MongoDB.
  *
  * @author Mark Paluch
+ * @author Christoph Strobl
  */
 @SpringBootApplication
 class ApplicationConfiguration {
 
 	/**
-	 * Callback to update {@link ImmutablePerson}.
+	 * Register the {@link BeforeConvertCallback} used to update an {@link ImmutablePerson} before handing over the newly
+	 * created instance to the actual mapping layer performing the conversion into the store native
+	 * {@link org.bson.Document} representation.
 	 *
 	 * @return a {@link BeforeConvertCallback} for {@link ImmutablePerson}.
 	 */
@@ -44,6 +47,7 @@ class ApplicationConfiguration {
 
 			int randomNumber = ThreadLocalRandom.current().nextInt(1, 100);
 
+			// withRandomNumber is a so called wither method returning a new instance of the entity with a new value assigned
 			return immutablePerson.withRandomNumber(randomNumber);
 		};
 	}
diff --git a/mongodb/example/src/main/java/example/springdata/mongodb/immutable/ImmutablePerson.java b/mongodb/example/src/main/java/example/springdata/mongodb/immutable/ImmutablePerson.java
index 6fd06e06..338ad07c 100644
--- a/mongodb/example/src/main/java/example/springdata/mongodb/immutable/ImmutablePerson.java
+++ b/mongodb/example/src/main/java/example/springdata/mongodb/immutable/ImmutablePerson.java
@@ -5,7 +5,7 @@
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
- *      http://www.apache.org/licenses/LICENSE-2.0
+ *      https://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
@@ -32,7 +32,6 @@ import org.bson.types.ObjectId;
 public class ImmutablePerson {
 
 	private final ObjectId id;
-
 	private final int randomNumber;
 
 	public ImmutablePerson() {
diff --git a/mongodb/example/src/test/java/example/springdata/mongodb/immutable/ImmutableEntityIntegrationTest.java b/mongodb/example/src/test/java/example/springdata/mongodb/immutable/ImmutableEntityIntegrationTest.java
index ef59bf16..950dcaea 100644
--- a/mongodb/example/src/test/java/example/springdata/mongodb/immutable/ImmutableEntityIntegrationTest.java
+++ b/mongodb/example/src/test/java/example/springdata/mongodb/immutable/ImmutableEntityIntegrationTest.java
@@ -5,7 +5,7 @@
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
- *      http://www.apache.org/licenses/LICENSE-2.0
+ *      https://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
@@ -20,7 +20,6 @@ import static org.assertj.core.api.Assertions.*;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
-
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.data.mongodb.core.MongoOperations;
@@ -30,6 +29,7 @@ import org.springframework.test.context.junit4.SpringRunner;
  * Integration test for {@link ImmutablePerson} showing features around immutable object support.
  *
  * @author Mark Paluch
+ * @author Christoph Strobl
  */
 @RunWith(SpringRunner.class)
 @SpringBootTest
@@ -39,8 +39,7 @@ public class ImmutableEntityIntegrationTest {
 
 	@Before
 	public void setUp() {
-
-		operations.remove(ImmutablePerson.class);
+		operations.dropCollection(ImmutablePerson.class);
 	}
 
 	/**