diff --git a/src/lm/preprocessing.rs b/src/lm/preprocessing.rs
index 7f5c114..4a370dc 100644
--- a/src/lm/preprocessing.rs
+++ b/src/lm/preprocessing.rs
@@ -18,24 +18,19 @@ mod tests{
     #[test]
     fn test(){
         let sentence = vec!["a","b", "c"];
-        let bigrams = padded_everygrams(sentence.iter(),2);
-        for b in bigrams.into_iter(){
-            for o in b{
-                print!("{}, ",o);
-            }
-            println!();
-        }
-        // let bigram1 = vec!["<s>"];
-        // let bigram2 = vec!["<s>", "a"];
-        // let bigram3 = vec!["a"];
-        // let bigram4 = vec!["a", "b"];
-        // let bigram5 = vec!["b"];
-        // let bigram6 = vec!["b", "c"];
-        // let bigram7 = vec!["c"];
-        // let bigram8 = vec!["c", "</s>"];
-        // let bigram9 = vec!["</s>"];
-        // let expected = vec![bigram1.iter(), bigram2.iter(), bigram3.iter(), bigram4.iter(), bigram5.iter(), bigram6.iter(),bigram7.iter(),bigram8.iter(),bigram9.iter()];
-        //
-        // crate::test::should_be_equal_list_of_lists(&mut bigrams, expected)
+        let mut bigrams = padded_everygrams(sentence.iter(),2);
+
+        let bigram1 = vec!["<s>"];
+        let bigram2 = vec!["<s>", "a"];
+        let bigram3 = vec!["a"];
+        let bigram4 = vec!["a", "b"];
+        let bigram5 = vec!["b"];
+        let bigram6 = vec!["b", "c"];
+        let bigram7 = vec!["c"];
+        let bigram8 = vec!["c", "</s>"];
+        let bigram9 = vec!["</s>"];
+        let expected = vec![bigram1.iter(), bigram2.iter(), bigram3.iter(), bigram4.iter(), bigram5.iter(), bigram6.iter(),bigram7.iter(),bigram8.iter(),bigram9.iter()];
+
+        crate::test::should_be_equal_list_of_lists(&mut bigrams, expected)
     }
 }
\ No newline at end of file
diff --git a/src/test.rs b/src/test.rs
index 6641280..3a672b3 100644
--- a/src/test.rs
+++ b/src/test.rs
@@ -7,9 +7,11 @@ pub fn should_be_equal_lists<'a>(left: impl Iterator<Item=&'a &'a str>, right: V
 }
 
 pub fn should_be_equal_list_of_lists<'a>(actual: &mut impl Iterator<Item=impl Iterator<Item=&'a &'a str>>, expected: Vec<Iter<&'a str>>) {
-    for (actual_outer, expected_outer) in actual.zip(expected.into_iter()) {
+    let mut actual_vec=Vec::new();
+    actual_vec.extend(actual);
+    assert_eq!(actual_vec.len(), expected.len());
+    for (actual_outer, expected_outer) in actual_vec.into_iter().zip(expected.into_iter()) {
         for (actual_inner, expected_inner) in actual_outer.zip(expected_outer) {
-            // println!("{} {}", actual_inner, expected_inner);
             assert_eq!(actual_inner, expected_inner);
         }
     }