add factory make()

git-svn-id: https://wala.svn.sourceforge.net/svnroot/wala/trunk@1496 f5eafffb-2e1d-0410-98e4-8ec43c5233c4

com.ibm.wala.core/src/com/ibm/wala/util/collections/NonNullSingletonIterator.java

@@ -55,4 +55,8 @@ public class NonNullSingletonIterator<T> implements Iterator<T> {
     throw new UnsupportedOperationException();
   }
 
+  public static <T> NonNullSingletonIterator<T> make(T item) {
+    return new NonNullSingletonIterator<T>(item);
+  }
+
 }