Replace Collections.unmodifiableList with guava ImmutableList

 package org.onlab.onos.store.service;
 
-import java.util.Collections;
 import java.util.List;
 
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Lists;
 
 /**
@@ -22,7 +22,7 @@ public final class BatchReadRequest {
     }
 
     private BatchReadRequest(List<ReadRequest> readRequests) {
-        this.readRequests = Collections.unmodifiableList(readRequests);
+        this.readRequests = ImmutableList.copyOf(readRequests);
     }
 
     /**

 package org.onlab.onos.store.service;
 
-import java.util.Collections;
 import java.util.List;
 
+import com.google.common.collect.ImmutableList;
+
 /**
  * Result of a batch read operation.
  */
@@ -11,7 +12,7 @@ public class BatchReadResult {
     private final List<ReadResult> readResults;
 
     public BatchReadResult(List<ReadResult> readResults)  {
-        this.readResults = Collections.unmodifiableList(readResults);
+        this.readResults = ImmutableList.copyOf(readResults);
     }
 
     /**

 package org.onlab.onos.store.service;
 
-import java.util.Collections;
 import java.util.List;
 
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Lists;
 
 /**
@@ -22,7 +22,7 @@ public final class BatchWriteRequest {
     }
 
     private BatchWriteRequest(List<WriteRequest> writeRequests) {
-        this.writeRequests = Collections.unmodifiableList(writeRequests);
+        this.writeRequests = ImmutableList.copyOf(writeRequests);
     }
 
     /**

 package org.onlab.onos.store.service;
 
-import java.util.Collections;
 import java.util.List;
 
+import com.google.common.collect.ImmutableList;
+
 /**
  * Result of a batch write operation.
  */
@@ -11,7 +12,7 @@ public class BatchWriteResult {
     private final List<WriteResult> writeResults;
 
     public BatchWriteResult(List<WriteResult> writeResults) {
-        this.writeResults = Collections.unmodifiableList(writeResults);
+        this.writeResults = ImmutableList.copyOf(writeResults);
     }
 
     /**