docs: def _netmiko_open(self, device_type, netmiko_optional_args=None):
          """Standardized method of creating a Netmiko connection using napalm attributes."""
          if netmiko_optional_args is None:
              netmiko_optional_args = {}
          try:
              self._netmiko_device = ConnectHandler(
                  device_type=device_type,
                  host=self.hostname,
                  username=self.username,
                  password=self.password,
                  timeout=self.timeout,
                  **netmiko_optional_args
              )
          except NetMikoTimeoutException:
              raise ConnectionException("Cannot connect to {}".format(self.hostname))
  
          # ensure in enable mode
          self._netmiko_device.enable()
          return self._netmiko_device