diff --git a/src/main/java/org/caosdb/server/entity/MagicTypes.java b/src/main/java/org/caosdb/server/entity/MagicTypes.java
index cffdb0723588d3aaec31e24a39895e304aa2e18b..f17d448ca934901dc491f1d737f9122e2a67862a 100644
--- a/src/main/java/org/caosdb/server/entity/MagicTypes.java
+++ b/src/main/java/org/caosdb/server/entity/MagicTypes.java
@@ -26,6 +26,7 @@ import java.util.HashMap;
 import org.caosdb.server.entity.container.RetrieveContainer;
 import org.caosdb.server.transaction.Retrieve;
 
+/** Some types correspond to entities in the database with magic IDs. */
 public enum MagicTypes {
   UNIT,
   NAME,
diff --git a/src/main/java/org/caosdb/server/grpc/EntityTransactionServiceImpl.java b/src/main/java/org/caosdb/server/grpc/EntityTransactionServiceImpl.java
index ca8f636472dd6b20191cd20abaf57ccd92b5c80c..0b5dd7e102e3b6f374ccfe28ddde2c73dbdd5cfb 100644
--- a/src/main/java/org/caosdb/server/grpc/EntityTransactionServiceImpl.java
+++ b/src/main/java/org/caosdb/server/grpc/EntityTransactionServiceImpl.java
@@ -7,6 +7,8 @@ import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.UUID;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.apache.shiro.SecurityUtils;
 import org.caosdb.api.entity.v1alpha1.AtomicDataType;
 import org.caosdb.api.entity.v1alpha1.CollectionValues;
@@ -85,6 +87,7 @@ public class EntityTransactionServiceImpl extends EntityTransactionServiceImplBa
 
   private final FileTransmissionServiceImpl fileTransmissionService;
 
+  /** Get the unit as string. */
   public String getStringUnit(final EntityInterface entity) {
     final Iterator<Property> iterator = entity.getProperties().iterator();
     while (iterator.hasNext()) {