text: ////////////////////////////////////////////////////////////////////////////////
  /// DISCLAIMER
  ///
  /// Copyright 2014-2020 ArangoDB GmbH, Cologne, Germany
  /// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
  ///
  /// Licensed 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
  /// distributed under the License is distributed on an "AS IS" BASIS,
  /// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  /// See the License for the specific language governing permissions and
  /// limitations under the License.
  ///
  /// Copyright holder is ArangoDB GmbH, Cologne, Germany
  ///
  /// @author Kaveh Vahedipour
  ////////////////////////////////////////////////////////////////////////////////
  
  #ifndef ARANGOD_CONSENSUS_INCEPTION_H
  #define ARANGOD_CONSENSUS_INCEPTION_H 1
  
  #include <memory>
  
  #include "Agency/AgencyCommon.h"
  #include "Basics/Common.h"
  #include "Basics/ConditionVariable.h"
  #include "Basics/Mutex.h"
  #include "Basics/Thread.h"
  
  #include <velocypack/Builder.h>
  #include <velocypack/velocypack-aliases.h>
  
  namespace arangodb {
  namespace consensus {
  
  class Agent;
  
  /// @brief This class organizes the startup of the agency until the point
  ///        where the RAFT implementation can commence function
  class Inception : public Thread {
   public:
    /// @brief Construct with agent
    explicit Inception(Agent&);
  
    /// @brief Defualt dtor
    virtual ~Inception();
  
    /// @brief Report acknowledged version for peer id
    void reportVersionForEp(std::string const&, size_t);
  
    void beginShutdown() override;
    void run() override;
  
    void signalConditionVar();
  
   private:
    /// @brief We are a restarting active RAFT agent
    ///
    /// Make sure that majority of agents agrees on pool and active list.
    /// Subsequently, start agency. The exception to agreement over active agent
    /// list among peers is if an agent joins with empty active list. This allows
    /// for a peer with empty list to join nevertheless.
    /// The formation of an agency is tried for an hour before giving up.
    bool restartingActiveAgent();
  
    /// @brief Gossip your way into the agency
    ///
    /// No persistence: gossip an agency together.
    void gossip();
  
    Agent& _agent;                            //< @brief The agent
    arangodb::basics::ConditionVariable _cv;  //< @brief For proper shutdown
    std::unordered_map<std::string, size_t> _acked;  //< @brief acknowledged config version
    mutable arangodb::Mutex _vLock;                  //< @brieg Guard _acked
  };
  
  }  // namespace consensus
  }  // namespace arangodb
  
  #endif
  