Returns the rendered navigation block. Requires that the
    `navigation.html` template exists. Two context variables are passed to it:

    * sections (see :func:`get_breadcrumb_sections`)
    * trail (see :func:`get_breadcrumb_trail`)

def get_navigation(request):
    """ Returns the rendered navigation block. Requires that the
    `navigation.html` template exists. Two context variables are passed to it:

    * sections (see :func:`get_breadcrumb_sections`)
    * trail (see :func:`get_breadcrumb_trail`)

    """
    sections = _get_sections(request)
    trail = _get_trail(request, exclude_section=True)

    return mark_safe(render_to_string('navigation.html',
                                      dict(sections=sections,trail=trail)))