content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
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   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
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   * See the License for the specific language governing permissions and
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  package org.apache.cassandra.service.paxos;
  
  import org.apache.cassandra.distributed.Cluster;
  import org.apache.cassandra.distributed.api.IMessageFilters;
  import org.apache.cassandra.net.Message;
  import org.apache.cassandra.tcm.Epoch;
  
  import static org.apache.cassandra.distributed.impl.Instance.deserializeMessage;
  import static org.junit.Assert.assertTrue;
  
  public class MessageHelper
  {
      public static IMessageFilters.Matcher electorateMismatchChecker(final Cluster cluster)
      {
          return (from, to, msg) -> {
              cluster.get(to).runOnInstance(() -> {
                  Message<?> message = deserializeMessage(msg);
                  if (message.payload instanceof PaxosPrepare.Response)
                  {
                      PaxosPrepare.Permitted permitted = ((PaxosPrepare.Response)message.payload).permitted();
                      assertTrue(permitted.gossipInfo.isEmpty());
                      assertTrue(permitted.electorateEpoch.is(Epoch.EMPTY));
                  }
              });
              return false;
          };
      }
  }
  