diff --git a/src/main/java/org/ids_mannheim/Worker.java b/src/main/java/org/ids_mannheim/Worker.java
index 723e570..ff855d4 100644
--- a/src/main/java/org/ids_mannheim/Worker.java
+++ b/src/main/java/org/ids_mannheim/Worker.java
@@ -1,9 +1,8 @@
 package org.ids_mannheim;
 
-import java.io.BufferedReader;
-import java.io.File;
-import java.io.IOException;
-import java.io.InputStreamReader;
+import org.anarres.parallelgzip.ParallelGZIPInputStream;
+
+import java.io.*;
 import java.util.ArrayList;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.ConcurrentHashMap;
@@ -12,6 +11,7 @@
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import static java.lang.String.join;
 import static java.lang.Thread.sleep;
 
 public class Worker implements Runnable {