Index: src/main/java/org/apache/pdfbox/contentstream/operator/state/EmptyGraphicsStackException.java
===================================================================
--- src/main/java/org/apache/pdfbox/contentstream/operator/state/EmptyGraphicsStackException.java	(Revision 1666534)
+++ src/main/java/org/apache/pdfbox/contentstream/operator/state/EmptyGraphicsStackException.java	(Arbeitskopie)
@@ -24,6 +24,11 @@
  */
 public final class EmptyGraphicsStackException extends IOException
 {
+    /**
+     * 
+     */
+    private static final long serialVersionUID = 1L;
+
     EmptyGraphicsStackException()
     {
         super("Cannot execute restore, the graphics stack is empty");
Index: src/main/java/org/apache/pdfbox/contentstream/operator/state/Restore.java
===================================================================
--- src/main/java/org/apache/pdfbox/contentstream/operator/state/Restore.java	(Revision 1666534)
+++ src/main/java/org/apache/pdfbox/contentstream/operator/state/Restore.java	(Arbeitskopie)
@@ -19,11 +19,9 @@
 import java.io.IOException;
 import java.util.List;
 
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-import org.apache.pdfbox.cos.COSBase;
 import org.apache.pdfbox.contentstream.operator.Operator;
 import org.apache.pdfbox.contentstream.operator.OperatorProcessor;
+import org.apache.pdfbox.cos.COSBase;
 
 /**
  * Q: Restore the graphics state.
@@ -32,8 +30,6 @@
  */
 public class Restore extends OperatorProcessor
 {
-    private static final Log LOG = LogFactory.getLog(Restore.class);
-
     @Override
     public void process(Operator operator, List<COSBase> arguments) throws IOException
     {