Various improvements for pre-written base types (U8 etc.)
diff --git a/java_gen/pre-written/src/main/java/org/openflow/types/U8.java b/java_gen/pre-written/src/main/java/org/openflow/types/U8.java
index 2bd34bf..c15be0e 100644
--- a/java_gen/pre-written/src/main/java/org/openflow/types/U8.java
+++ b/java_gen/pre-written/src/main/java/org/openflow/types/U8.java
@@ -22,7 +22,7 @@
 import org.openflow.protocol.OFMessageReader;
 import org.openflow.protocol.Writeable;
 
-public class U8 implements Writeable {
+public class U8 implements Writeable, OFValueType<U8> {
     private final byte raw;
 
     private U8(byte raw) {
@@ -96,4 +96,14 @@
         }
     }
 
+    @Override
+    public int getLength() {
+        return 1;
+    }
+
+    @Override
+    public U8 applyMask(U8 mask) {
+        return ofRaw( (byte) (raw & mask.raw));
+    }
+
 }