async def METHOD_NAME(self, mock_command, mock_app):
    mock_permissions = object()
    result = await mock_command.set_guild_permissions(312123, mock_permissions)
    assert result is mock_app.rest.set_application_command_permissions.return_value
    mock_app.rest.set_application_command_permissions.assert_awaited_once_with(
        application=mock_command.application_id, guild=312123, command=mock_command.id, permissions=mock_permissions
    )