Err too much.

me/cache/helpers/TunnelCollection.java

@@ -0,0 +1,37 @@
+package appeng.me.cache.helpers;
+
+import java.util.Collection;
+import java.util.Iterator;
+
+import appeng.parts.p2p.PartP2PTunnel;
+import appeng.util.iterators.NullIterator;
+
+public class TunnelCollection<T extends PartP2PTunnel> implements Iterable<T>
+{
+
+	final Class clz;
+	Collection<T> tunnelsource;
+
+	public TunnelCollection(Collection<T> src, Class c) {
+		tunnelsource = src;
+		clz = c;
+	}
+
+	@Override
+	public Iterator<T> iterator()
+	{
+		if ( tunnelsource == null )
+			return new NullIterator();
+		return new TunnelIterator( tunnelsource, clz );
+	}
+
+	public void setSource(Collection<T> c)
+	{
+		tunnelsource = c;
+	}
+
+	public boolean isEmpty()
+	{
+		return iterator().hasNext();
+	}
+}

me/cache/helpers/TunnelIterator.java

@@ -0,0 +1,52 @@
+package appeng.me.cache.helpers;
+
+import java.util.Collection;
+import java.util.Iterator;
+
+import appeng.parts.p2p.PartP2PTunnel;
+
+public class TunnelIterator<T extends PartP2PTunnel> implements Iterator<T>
+{
+
+	Iterator<T> wrapped;
+	Class targetType;
+	T Next;
+
+	private void findNext()
+	{
+		while (Next == null && wrapped.hasNext())
+		{
+			Next = wrapped.next();
+			if ( !targetType.isInstance( Next ) )
+				Next = null;
+		}
+	}
+
+	public TunnelIterator(Collection<T> tunnelsource, Class clz) {
+		wrapped = tunnelsource.iterator();
+		targetType = clz;
+		findNext();
+	}
+
+	@Override
+	public boolean hasNext()
+	{
+		findNext();
+		return Next != null;
+	}
+
+	@Override
+	public T next()
+	{
+		T tmp = Next;
+		Next = null;
+		return tmp;
+	}
+
+	@Override
+	public void remove()
+	{
+		// no.
+	}
+
+}