code: def _get_pkey(self):
          
          keypath = self.config.server["pkey"]
          with open(os.path.expanduser(keypath)) as f:
              pkey = paramiko.RSAKey.from_private_key(f)
  
          return pkey
docs: Gets an RSAKey object for the private key file so that we can
          copy files without logging in with user/password.