diff --git a/src/main/java/com/datumbox/common/dataobjects/Dataframe.java b/src/main/java/com/datumbox/common/dataobjects/Dataframe.java
index <HASH>..<HASH> 100644
--- a/src/main/java/com/datumbox/common/dataobjects/Dataframe.java
+++ b/src/main/java/com/datumbox/common/dataobjects/Dataframe.java
@@ -32,7 +32,6 @@ import java.util.Collections;
 import java.util.HashMap;

 import java.util.Iterator;

 import java.util.Map;

-import java.util.Random;

 import java.util.Set;

 import org.apache.commons.csv.CSVFormat;

 import org.apache.commons.csv.CSVParser;

@@ -277,7 +276,7 @@ public final class Dataframe implements Serializable, Collection<Record> {
      */

     @Override

     public boolean contains(Object o) {

-        return records.containsValue(o);

+        return records.containsValue((Record)o);

     }

     

     /**

@@ -386,7 +385,7 @@ public final class Dataframe implements Serializable, Collection<Record> {
     public boolean removeAll(Collection<?> c) {

         boolean modified = false;

         for(Object o : c) {

-            modified |= remove(o);

+            modified |= remove((Record)o);

         }

         if(modified) {

             recalculateMeta();
Fixing imports and casts.