def masked(name, runtime=False):
    '''
    .. versionadded:: 2017.7.0

    .. note::
        This state is only available on minions which use systemd_.

    Ensures that the named service is masked (i.e. prevented from being
    started).

    name
        Name of the service to mask

    runtime : False
        By default, this state will manage an indefinite mask for the named
        service. Set this argument to ``True`` to runtime mask the service.

    .. note::
        It is possible for a service to have both indefinite and runtime masks
        set for it. Therefore, this state will manage a runtime or indefinite
        mask independently of each other. This means that if the service is
        already indefinitely masked, running this state with ``runtime`` set to
        ``True`` will _not_ remove the indefinite mask before setting a runtime
        mask. In these cases, if it is desirable to ensure that the service is
        runtime masked and not indefinitely masked, pair this state with a
        :py:func:`service.unmasked <salt.states.service.unmasked>` state, like
        so:

        .. code-block:: yaml

            mask_runtime_foo:
              service.masked:
                - name: foo
                - runtime: True

            unmask_indefinite_foo:
              service.unmasked:
                - name: foo
                - runtime: False

    .. _systemd: https://freedesktop.org/wiki/Software/systemd/

    '''
    ret = {'name': name,
           'changes': {},
           'result': True,
           'comment': ''}

    if 'service.masked' not in __salt__:
        ret['comment'] = 'Service masking not available on this minion'
        ret['result'] = False
        return ret

    mask_type = 'runtime masked' if runtime else 'masked'
    expected_changes = {mask_type: {'old': False, 'new': True}}

    try:
        if __salt__['service.masked'](name, runtime):
            ret['comment'] = 'Service {0} is already {1}'.format(
                name,
                mask_type,
            )
            return ret

        if __opts__['test']:
            ret['result'] = None
            ret['changes'] = expected_changes
            ret['comment'] = 'Service {0} would be {1}'.format(name, mask_type)
            return ret

        __salt__['service.mask'](name, runtime)

        if __salt__['service.masked'](name, runtime):
            ret['changes'] = expected_changes
            ret['comment'] = 'Service {0} was {1}'.format(name, mask_type)
        else:
            ret['comment'] = 'Failed to mask service {0}'.format(name)
        return ret

    except CommandExecutionError as exc:
        ret['result'] = False
        ret['comment'] = exc.strerror
        return ret