diff --git a/src/de/uni_passau/fim/seibt/gitwrapper/repo/Branch.java b/src/de/uni_passau/fim/seibt/gitwrapper/repo/Branch.java
index 32abd4f209858e874173537bae462e9711d0db82..8fcf1d52cf824e29f020757746ce0118fa423970 100644
--- a/src/de/uni_passau/fim/seibt/gitwrapper/repo/Branch.java
+++ b/src/de/uni_passau/fim/seibt/gitwrapper/repo/Branch.java
@@ -4,9 +4,12 @@ import de.uni_passau.fim.seibt.gitwrapper.process.ProcessExecutor;
 
 import java.util.Optional;
 import java.util.function.Function;
+import java.util.logging.Logger;
 
 public class Branch extends Reference {
 
+    private static final Logger LOG = Logger.getLogger(Branch.class.getCanonicalName());
+
     Branch(Repository repo, String name) {
         super(repo, name);
     }
@@ -20,6 +23,7 @@ public class Branch extends Reference {
         if (!repo.checkout(this)) {
             return false;
         }
+
         Optional<ProcessExecutor.ExecRes> fetch = git.exec(repo.getDir(), "pull");
         Function<ProcessExecutor.ExecRes, Boolean> toBoolean = res -> {
             boolean failed = git.failed(res);
@@ -46,6 +50,7 @@ public class Branch extends Reference {
 
     /**
      * Reruns the branch name
+     *
      * @return the branch name
      */
     public String getName() {
diff --git a/src/de/uni_passau/fim/seibt/gitwrapper/repo/Commit.java b/src/de/uni_passau/fim/seibt/gitwrapper/repo/Commit.java
index 4a26037e0fa58ba0ae40e6d79652580e704c623d..6cccf32f42364cb26a6bee94b2d163f0d29805bc 100644
--- a/src/de/uni_passau/fim/seibt/gitwrapper/repo/Commit.java
+++ b/src/de/uni_passau/fim/seibt/gitwrapper/repo/Commit.java
@@ -3,6 +3,7 @@ package de.uni_passau.fim.seibt.gitwrapper.repo;
 import java.time.Instant;
 import java.time.OffsetDateTime;
 import java.time.ZoneId;
+import java.util.logging.Logger;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -10,6 +11,7 @@ import java.util.regex.Pattern;
  * A {@link Commit} made in a {@link Repository}.
  */
 public class Commit extends Reference {
+    private static final Logger LOG = Logger.getLogger(Commit.class.getCanonicalName());
 
     // since there is no porcelain format for this command, this regex is might depend on the git version
     private static final Pattern TREE_INFO = Pattern.compile("tree (.{40})\\nparent (.{40})\\n");
diff --git a/src/de/uni_passau/fim/seibt/gitwrapper/repo/DummyCommit.java b/src/de/uni_passau/fim/seibt/gitwrapper/repo/DummyCommit.java
index 347d0ecdff1c8a3f7db322b8c420dd1f2a594fc3..1b082256477fcd9bf98f918dcf6777d281c84cfa 100644
--- a/src/de/uni_passau/fim/seibt/gitwrapper/repo/DummyCommit.java
+++ b/src/de/uni_passau/fim/seibt/gitwrapper/repo/DummyCommit.java
@@ -59,7 +59,7 @@ public class DummyCommit extends Commit {
     }
 
     private void setterWarning() {
-        LOG.warning(() -> "Ignoring a setter call on the DummyCommit for " + repo);
+        LOG.finest(() -> "Ignoring a setter call on the DummyCommit for " + repo);
         // TODO gets called often while parsing blame lines, maybe change level
     }
 }
diff --git a/src/de/uni_passau/fim/seibt/gitwrapper/repo/Reference.java b/src/de/uni_passau/fim/seibt/gitwrapper/repo/Reference.java
index 96d46cc10a0c3e4eb4018edc76d9d6dbc4f704b7..d44394d8c33fb3f493430158f5305b13a5531b85 100644
--- a/src/de/uni_passau/fim/seibt/gitwrapper/repo/Reference.java
+++ b/src/de/uni_passau/fim/seibt/gitwrapper/repo/Reference.java
@@ -8,7 +8,8 @@ import java.util.logging.Logger;
 import java.util.stream.Collectors;
 
 public abstract class Reference {
-    protected static final Logger LOG = Logger.getLogger(Commit.class.getCanonicalName());
+
+    private static final Logger LOG = Logger.getLogger(Reference.class.getCanonicalName());
 
     protected final String id;
     protected final Repository repo;
@@ -32,7 +33,6 @@ public abstract class Reference {
      * @return the merge base or an empty {@link Optional} if there is no merge base or an exception occurred
      */
     public Optional<Commit> getMergeBase(Reference other) {
-
         if (!repo.equals(other.repo)) {
             LOG.warning(() -> {
                 String msg = "Failed to obtain a merge base for %s and %s as they are not from the same repository.";
@@ -67,10 +67,11 @@ public abstract class Reference {
      * @param other the {@link Reference} to merge
      * @return <code>false</code>, if the merge failed, or contains conflicts.
      */
-    public Boolean merge(Reference other) {
+    public boolean merge(Reference other) {
         if (!repo.checkout(this)) {
             return false;
         }
+
         Optional<ProcessExecutor.ExecRes> mergeBase = git.exec(repo.getDir(), "merge", "-n", "-q", other.getId());
         Function<ProcessExecutor.ExecRes, Boolean> toBoolean = res -> {
             if (git.failed(res)) {
@@ -106,7 +107,7 @@ public abstract class Reference {
     }
 
     @Override
-    public boolean equals(Object o) {
+    public final boolean equals(Object o) {
         if (this == o) {
             return true;
         }
@@ -120,7 +121,7 @@ public abstract class Reference {
     }
 
     @Override
-    public int hashCode() {
+    public final int hashCode() {
         return Objects.hash(repo, id);
     }
 
diff --git a/src/de/uni_passau/fim/seibt/gitwrapper/repo/Repository.java b/src/de/uni_passau/fim/seibt/gitwrapper/repo/Repository.java
index f06cef69438b9e7e2c083c1b96073dc863811eec..bde6b208740afb84bb91b6d763ccb6769eadf4e8 100644
--- a/src/de/uni_passau/fim/seibt/gitwrapper/repo/Repository.java
+++ b/src/de/uni_passau/fim/seibt/gitwrapper/repo/Repository.java
@@ -214,7 +214,6 @@ public class Repository {
      * @return the {@link Commit} or an empty {@link Optional} if the ID is invalid or an exception occurs
      */
     public Optional<Commit> getCommit(String id) {
-
         if (commits.containsKey(id)) {
             return Optional.of(commits.get(id));
         }
@@ -327,7 +326,6 @@ public class Repository {
      * @see FileUtils#copyDirectory(File, File)
      */
     public Optional<Repository> copy(File destination) {
-
         try {
             if (destination.exists() && destination.isDirectory()) {
                 LOG.warning(() -> String.format("%s already exists. Merging source and destination directories.", destination));
@@ -455,9 +453,11 @@ public class Repository {
                         other.put(headerKey, lineScanner.nextLine().trim());
                 }
             }
+
             if (authorInstant != null && authorTZ != null) {
                 commit.setAuthorTime(OffsetDateTime.ofInstant(authorInstant, authorTZ));
             }
+
             if (committerInstant != null && committerTZ != null) {
                 commit.setCommitterTime(OffsetDateTime.ofInstant(committerInstant, committerTZ));
             }