OFPortBitMap: add functionality to iterate over the Ports

+ a factory function from a OFBitMask
diff --git a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/OFPortBitMap.java b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/OFPortBitMap.java
index b9c2b75..18ab8b0 100644
--- a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/OFPortBitMap.java
+++ b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/OFPortBitMap.java
@@ -1,5 +1,7 @@
 package org.projectfloodlight.openflow.types;
 
+import java.util.ArrayList;
+
 import javax.annotation.concurrent.Immutable;
 
 
@@ -61,6 +63,20 @@
         return builder.build();
     }
 
+    public static OFPortBitMap of(OFBitMask128 mask) {
+        return new OFPortBitMap(mask);
+    }
+
+    public Iterable<OFPort> getOnPorts() {
+        ArrayList<OFPort> ports = new ArrayList<>();
+        for(int i=0; i < 127; i++) {
+            if(!(this.mask.isOn(i))) {
+                ports.add(OFPort.of(i));
+            }
+        }
+        return ports;
+    }
+
     @Override
     public boolean equals(Object obj) {
         if (!(obj instanceof OFPortBitMap))