'Renders the tab to HTML.
:meth:`~horizon.tabs.Tab.get_context_data` method and
the :meth:`~horizon.tabs.Tab.get_template_name` method are called.
If :attr:`~horizon.tabs.Tab.preload` is ``False`` and ``force_load``
is not ``True``, or
either :meth:`~horizon.tabs.Tab.allowed` or
:meth:`~horizon.tabs.Tab.enabled` returns ``False`` this method will
return an empty string.'

def render(self):

    if (not self.load):
        return ''
    try:
        context = self.data
    except exceptions.Http302:
        raise
    except Exception:
        (exc_type, exc_value, exc_traceback) = sys.exc_info()
        raise six.reraise(TemplateSyntaxError, exc_value, exc_traceback)
    return render_to_string(self.get_template_name(self.request), context)
