[ndnSIM] face: Emulation mode of ndn::Face

Change-Id: Ib345978575104afa436296d2f5a824a39e3a9780
diff --git a/src/face.hpp b/src/face.hpp
index e5ccbba..99f6b5c 100644
--- a/src/face.hpp
+++ b/src/face.hpp
@@ -167,15 +167,6 @@
   Face(boost::asio::io_service& ioService);
 
   /**
-   * @brief Create Face using TcpTransport
-   *
-   * @param host IP address or hostname of the NDN forwarder
-   * @param port port number or service name of the NDN forwarder (**default**: "6363")
-   */
-  explicit
-  Face(const std::string& host, const std::string& port = "6363");
-
-  /**
    * @brief Create Face using given transport and KeyChain
    * @param transport the transport for lower layer communication. If nullptr,
    *                  a default transport will be used.
@@ -466,12 +457,12 @@
   shutdown();
 
   /**
-   * @return reference to IO service object
+   * @brief Return nullptr (cannot use IoService in simulations), preserved for API compatibility
    */
   boost::asio::io_service&
   getIoService()
   {
-    return m_ioService;
+    return *static_cast<boost::asio::io_service*>(nullptr);
   }
 
 NDN_CXX_PUBLIC_WITH_TESTS_ELSE_PROTECTED:
@@ -506,22 +497,8 @@
   asyncShutdown();
 
 private:
-  /// the IO service owned by this Face, could be null
-  unique_ptr<boost::asio::io_service> m_internalIoService;
-  /// the IO service used by this Face
-  boost::asio::io_service& m_ioService;
-
   shared_ptr<Transport> m_transport;
 
-  /**
-   * @brief if not null, a pointer to an internal KeyChain owned by Face
-   * @note if a KeyChain is supplied to constructor, this pointer will be null,
-   *       and the passed KeyChain is given to nfdController;
-   *       currently Face does not keep the KeyChain passed in constructor
-   *       because it's not needed, but this may change in the future
-   */
-  unique_ptr<KeyChain> m_internalKeyChain;
-
   unique_ptr<nfd::Controller> m_nfdController;
 
   class Impl;