Get the list of available instance sizes (flavors).

def flavor_list_paged(request, is_public=True, get_extras=False, marker=None,
                      paginate=False, sort_key="name", sort_dir="desc",
                      reversed_order=False):
    """Get the list of available instance sizes (flavors)."""
    has_more_data = False
    has_prev_data = False

    if paginate:
        if reversed_order:
            sort_dir = 'desc' if sort_dir == 'asc' else 'asc'
        page_size = utils.get_page_size(request)
        flavors = _nova.novaclient(request).flavors.list(is_public=is_public,
                                                         marker=marker,
                                                         limit=page_size + 1,
                                                         sort_key=sort_key,
                                                         sort_dir=sort_dir)
        flavors, has_more_data, has_prev_data = update_pagination(
            flavors, page_size, marker, reversed_order)
    else:
        flavors = _nova.novaclient(request).flavors.list(is_public=is_public)

    if get_extras:
        for flavor in flavors:
            flavor.extras = flavor_get_extras(request, flavor.id, True, flavor)

    return (flavors, has_more_data, has_prev_data)