remove unnecessary Exception declaration

Change-Id: If1c86ab88987fb4ef0db8beaa412c4dc030f5520

@@ -3,7 +3,6 @@ package org.onlab.util;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.ConcurrentMap;
 
 
-import org.apache.commons.lang3.concurrent.ConcurrentException;
 import org.apache.commons.lang3.concurrent.ConcurrentInitializer;
 import org.apache.commons.lang3.concurrent.ConcurrentInitializer;
 
 
 /**
 /**
@@ -27,7 +26,7 @@ public final class NewConcurrentHashMap<K, V>
     }
     }
 
 
     @Override
     @Override
-    public ConcurrentMap<K, V> get() throws ConcurrentException {
+    public ConcurrentMap<K, V> get() {
         return new ConcurrentHashMap<>();
         return new ConcurrentHashMap<>();
     }
     }
 }
 }