Enabled iterator() function

git-svn-id: file:///humgen/gsa-scr1/gsa-engineering/svn_contents/trunk@575 348d0f76-0448-11de-a6fe-93d51630548a

java/src/org/broadinstitute/sting/gatk/iterators/PushbackIterator.java

@@ -11,7 +11,7 @@ package org.broadinstitute.sting.gatk.iterators;
 
 import java.util.Iterator;
 
-public class PushbackIterator<T> implements Iterator<T> {
+public class PushbackIterator<T> implements Iterator<T>, Iterable<T> {
     Iterator<T> underlyingIterator;
     T pushedElement = null;
 
@@ -23,6 +23,10 @@ public class PushbackIterator<T> implements Iterator<T> {
         return pushedElement != null || underlyingIterator.hasNext();
     }
 
+    public Iterator<T> iterator() {
+        return this;
+    }
+
     public T peek() {
         T x = next();
         pushback(x);