diff --git a/converter-sbml/src/main/java/lcsb/mapviewer/converter/model/sbml/MultiPackageNamingUtils.java b/converter-sbml/src/main/java/lcsb/mapviewer/converter/model/sbml/MultiPackageNamingUtils.java
index 3b691a55b7d4836a72a426b1168cd857cabc0c1f..7e00c47184b997e5f7ac4d51b54cde5600feeea5 100644
--- a/converter-sbml/src/main/java/lcsb/mapviewer/converter/model/sbml/MultiPackageNamingUtils.java
+++ b/converter-sbml/src/main/java/lcsb/mapviewer/converter/model/sbml/MultiPackageNamingUtils.java
@@ -18,6 +18,11 @@ import lcsb.mapviewer.model.map.species.field.TranscriptionSite;
  *
  */
 public final class MultiPackageNamingUtils {
+  
+  /**
+   * Default logger.
+   */
+  @SuppressWarnings("unused")
   private static Logger logger = Logger.getLogger(MultiPackageNamingUtils.class);
 
   private static final String MINERVA_MODIFICATION_TYPE_PREFIX = "minerva_modification_type_";
diff --git a/converter-sbml/src/main/java/lcsb/mapviewer/converter/model/sbml/SbmlExporter.java b/converter-sbml/src/main/java/lcsb/mapviewer/converter/model/sbml/SbmlExporter.java
index 3e8819a342f1f91c004c230e26bdf9967e09cbb3..79d301288529c66102f0821255a94ecd6b9bda98 100644
--- a/converter-sbml/src/main/java/lcsb/mapviewer/converter/model/sbml/SbmlExporter.java
+++ b/converter-sbml/src/main/java/lcsb/mapviewer/converter/model/sbml/SbmlExporter.java
@@ -3,9 +3,7 @@ package lcsb.mapviewer.converter.model.sbml;
 import java.io.UnsupportedEncodingException;
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.HashMap;
 import java.util.HashSet;
-import java.util.Map;
 import java.util.Set;
 
 import javax.xml.stream.XMLStreamException;
@@ -19,7 +17,6 @@ import org.sbml.jsbml.ext.layout.Dimensions;
 import org.sbml.jsbml.ext.layout.Layout;
 import org.sbml.jsbml.ext.layout.LayoutModelPlugin;
 import org.sbml.jsbml.ext.multi.MultiModelPlugin;
-import org.sbml.jsbml.ext.multi.MultiSpeciesType;
 import org.sbml.jsbml.ext.render.GlobalRenderInformation;
 import org.sbml.jsbml.ext.render.RenderLayoutPlugin;
 
@@ -142,15 +139,12 @@ public class SbmlExporter {
     return layout;
   }
 
-  private Map<Class<?>, MultiSpeciesType> speciesTypeByClass = new HashMap<>();
-
   protected MultiModelPlugin createSbmlMultiPlugin(Model result) {
     MultiModelPlugin multiPlugin = new MultiModelPlugin(result);
     result.addExtension("multi", multiPlugin);
     return multiPlugin;
   }
 
-
   /**
    * Creates SBML render plugin for SBML model.
    * 
diff --git a/converter-sbml/src/main/java/lcsb/mapviewer/converter/model/sbml/reaction/SbmlReactionExporter.java b/converter-sbml/src/main/java/lcsb/mapviewer/converter/model/sbml/reaction/SbmlReactionExporter.java
index 257a39e6ce645ffac9fa5837eb2476b8d1008a62..1c0323f3267b8ea24b9ec972c8b982de815f2982 100644
--- a/converter-sbml/src/main/java/lcsb/mapviewer/converter/model/sbml/reaction/SbmlReactionExporter.java
+++ b/converter-sbml/src/main/java/lcsb/mapviewer/converter/model/sbml/reaction/SbmlReactionExporter.java
@@ -17,7 +17,6 @@ import org.sbml.jsbml.Species;
 import org.sbml.jsbml.SpeciesReference;
 import org.sbml.jsbml.ext.layout.AbstractReferenceGlyph;
 import org.sbml.jsbml.ext.layout.Curve;
-import org.sbml.jsbml.ext.layout.Layout;
 import org.sbml.jsbml.ext.layout.LineSegment;
 import org.sbml.jsbml.ext.layout.Point;
 import org.sbml.jsbml.ext.layout.ReactionGlyph;
@@ -51,10 +50,15 @@ public class SbmlReactionExporter extends SbmlBioEntityExporter<Reaction, org.sb
   /**
    * Default class logger.
    */
+  @SuppressWarnings("unused")
   private static Logger logger = Logger.getLogger(SbmlReactionExporter.class);
+
   private SbmlBioEntityExporter<lcsb.mapviewer.model.map.species.Species, Species> speciesExporter;
+
   private SbmlBioEntityExporter<Compartment, org.sbml.jsbml.Compartment> compartmentExporter;
 
+  private Map<ReactionNode, SimpleSpeciesReference> speciesReferenceByReactionNode = new HashMap<>();
+
   public SbmlReactionExporter(Model sbmlModel, lcsb.mapviewer.model.map.model.Model minervaModel,
       SbmlBioEntityExporter<lcsb.mapviewer.model.map.species.Species, Species> speciesExporter,
       Collection<SbmlExtension> sbmlExtensions,
@@ -64,8 +68,6 @@ public class SbmlReactionExporter extends SbmlBioEntityExporter<Reaction, org.sb
     this.compartmentExporter = compartmentExporter;
   }
 
-  Map<ReactionNode, SimpleSpeciesReference> speciesReferenceByReactionNode = new HashMap<>();
-
   @Override
   public org.sbml.jsbml.Reaction createSbmlElement(Reaction reaction) throws InconsistentModelException {
     String reactionId = getReactionId(reaction);