Match field iteration
diff --git a/java_gen/templates/_imports.java b/java_gen/templates/_imports.java
index 2187bab..cf7334d 100644
--- a/java_gen/templates/_imports.java
+++ b/java_gen/templates/_imports.java
@@ -1,6 +1,7 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.EnumSet;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Set;
 import java.util.Map;
@@ -21,5 +22,6 @@
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Sets;
+import com.google.common.collect.UnmodifiableIterator;
 import com.google.common.hash.Funnel;
 import com.google.common.hash.PrimitiveSink;