'Executes a CLI command on the device
:arg cmd: Byte string consisting of the command to execute
:kwarg check_rc: If True, the default, raise an
:exc:`AnsibleConnectionFailure` if the return code from the
command is nonzero
:returns: A tuple of return code, stdout, and stderr from running the
command.  stdout and stderr are both byte strings.'

def _exec_cli_command(self, cmd, check_rc=True):

    (rc, out, err) = self._connection.exec_command(cmd)
    if (check_rc and (rc != 0)):
        raise AnsibleConnectionFailure(err)
    return (rc, out, err)
