1 files changed, 8 insertions, 10 deletions

diff --git a/src/uk/ac/ox/cs/pagoda/reasoner/QueryEngine.java b/src/uk/ac/ox/cs/pagoda/reasoner/QueryEngine.java
index b9abf07..3200216 100644
--- a/src/uk/ac/ox/cs/pagoda/reasoner/QueryEngine.java
+++ b/src/uk/ac/ox/cs/pagoda/reasoner/QueryEngine.java
@@ -1,17 +1,15 @@
 package uk.ac.ox.cs.pagoda.reasoner;
 
+import uk.ac.ox.cs.pagoda.query.AnswerTuples;
+import uk.ac.ox.cs.pagoda.util.disposable.Disposable;
+
 import java.util.Collection;
 
-import uk.ac.ox.cs.pagoda.query.AnswerTuples;
+public abstract class QueryEngine extends Disposable {
+
+        public abstract void evaluate(Collection<String> queryTexts, String answerFile);
 
-public interface QueryEngine {
+        public abstract AnswerTuples evaluate(String queryText);
 
-        public void evaluate(Collection<String> queryTexts, String answerFile);
-        
-        public AnswerTuples evaluate(String queryText);
-        
-        public AnswerTuples evaluate(String queryText, String[] answerVariables);
-        
-        public void dispose(); 
-        
+        public abstract AnswerTuples evaluate(String queryText, String[] answerVariables);
 }