code: def install(cls, mbox):
      
      def wrap(fn):
        setattr(fn, cls.INSTALL_ATTRIBUTE, mbox)
        return fn
      return wrap
docs: A decorator to indicate a remotely callable method on a process.
  
      .. code-block:: python
  
          from compactor.process import Process
  
          class PingProcess(Process):
            @Process.install('ping')
            def ping(self, from_pid, body):
              # do something
  
      The installed method should take ``from_pid`` and ``body`` parameters.
      ``from_pid`` is the process calling the method.  ``body`` is a ``bytes``
      stream that was delivered with the message, possibly empty.
  
      :param mbox: Incoming messages to this "mailbox" will be dispatched to this method.
      :type mbox: ``str``