diff --git a/jode/jode/expr/CheckNullOperator.java b/jode/jode/expr/CheckNullOperator.java
index bf6e9a8..1f90207 100644
--- a/jode/jode/expr/CheckNullOperator.java
+++ b/jode/jode/expr/CheckNullOperator.java
@@ -23,9 +23,9 @@ import jode.decompiler.LocalInfo;
 import jode.decompiler.TabbedPrintWriter;
 
 ///#ifdef JDK12
-///import java.util.Set;
+///import java.util.Collection;
 ///#else
-import jode.util.Set;
+import jode.util.Collection;
 ///#endif
 
 /**
@@ -74,13 +74,13 @@ public class CheckNullOperator extends Operator {
 	local.remove();
     }
 
-    public void fillInGenSet(Set in, Set gen) {
+    public void fillInGenSet(Collection in, Collection gen) {
 	if (gen != null)
 	    gen.add(local);
 	super.fillInGenSet(in, gen);
     }
 
-    public void fillDeclarables(Set used) {
+    public void fillDeclarables(Collection used) {
 	used.add(local);
 	super.fillDeclarables(used);
     }
diff --git a/jode/jode/expr/ConstructorOperator.java b/jode/jode/expr/ConstructorOperator.java
index 5ebb177..4b4918e 100644
--- a/jode/jode/expr/ConstructorOperator.java
+++ b/jode/jode/expr/ConstructorOperator.java
@@ -33,9 +33,9 @@ import jode.decompiler.Scope;
 
 import java.lang.reflect.Modifier;
 ///#ifdef JDK12
-///import java.util.Set;
+///import java.util.Collection;
 ///#else
-import jode.util.Set;
+import jode.util.Collection;
 ///#endif
 
 public class ConstructorOperator extends Operator 
@@ -165,7 +165,7 @@ public class ConstructorOperator extends Operator
      * We add the named method scoped classes to the declarables, and
      * only fillDeclarables on the parameters we will print.
      */
-    public void fillDeclarables(Set used) {
+    public void fillDeclarables(Collection used) {
 	ClassInfo clazz = getClassInfo();
 	InnerClassInfo outer = getOuterClassInfo(clazz);
 	ClassAnalyzer clazzAna = methodAnalyzer.getClassAnalyzer(clazz);
diff --git a/jode/jode/expr/Expression.java b/jode/jode/expr/Expression.java
index afdbe00..63c8289 100644
--- a/jode/jode/expr/Expression.java
+++ b/jode/jode/expr/Expression.java
@@ -23,9 +23,9 @@ import jode.GlobalOptions;
 import jode.decompiler.TabbedPrintWriter;
 
 ///#ifdef JDK12
-///import java.util.Set;
+///import java.util.Collection;
 ///#else
-import jode.util.Set;
+import jode.util.Collection;
 ///#endif
 
 public abstract class Expression {
@@ -228,10 +228,10 @@ public abstract class Expression {
         return true;
     }
 
-    public void fillInGenSet(Set in, Set gen) {
+    public void fillInGenSet(Collection in, Collection gen) {
     }
 
-    public void fillDeclarables(Set used) {
+    public void fillDeclarables(Collection used) {
     }
 
     public abstract void dumpExpression(TabbedPrintWriter writer) 
diff --git a/jode/jode/expr/LocalStoreOperator.java b/jode/jode/expr/LocalStoreOperator.java
index 44e58ce..45dfcf5 100644
--- a/jode/jode/expr/LocalStoreOperator.java
+++ b/jode/jode/expr/LocalStoreOperator.java
@@ -35,6 +35,7 @@ public class LocalStoreOperator extends LValueExpression
     }
 
     public boolean isRead() {
+	/* if it is part of a += operator, this is a read. */
         return parent != null && parent.getOperatorIndex() != ASSIGN_OP;
     }
 
diff --git a/jode/jode/expr/Operator.java b/jode/jode/expr/Operator.java
index 950ebed..aafb43b 100644
--- a/jode/jode/expr/Operator.java
+++ b/jode/jode/expr/Operator.java
@@ -23,9 +23,9 @@ import jode.GlobalOptions;
 import jode.decompiler.TabbedPrintWriter;
 
 ///#ifdef JDK12
-///import java.util.Set;
+///import java.util.Collection;
 ///#else
-import jode.util.Set;
+import jode.util.Collection;
 ///#endif
 
 public abstract class Operator extends Expression {
@@ -163,7 +163,7 @@ public abstract class Operator extends Expression {
 	return this;
     }
 
-    public void fillInGenSet(Set in, Set gen) {
+    public void fillInGenSet(Collection in, Collection gen) {
 	if (this instanceof LocalVarOperator) {
             LocalVarOperator varOp = (LocalVarOperator) this;
             if (varOp.isRead() && in != null)
@@ -175,7 +175,7 @@ public abstract class Operator extends Expression {
 	    subExpressions[i].fillInGenSet(in,gen);
     }
 
-    public void fillDeclarables(Set used) {
+    public void fillDeclarables(Collection used) {
 	if (this instanceof LocalVarOperator) {
 	    used.add(((LocalVarOperator) this).getLocalInfo());
 	}