'Returns a list of all static assets for a course. The return format is a list of asset data dictionary elements.
The asset data dictionaries have the following keys:
asset_key (:class:`opaque_keys.edx.AssetKey`): The key of the asset
displayname: The human-readable name of the asset
uploadDate (datetime.datetime): The date and time that the file was uploadDate
contentType: The mimetype string of the asset
md5: An md5 hash of the asset content'

@autoretry_read()
def _get_all_content_for_course(self, course_key, get_thumbnails=False, start=0, maxresults=(-1), sort=None, filter_params=None):

    query = query_for_course(course_key, ('asset' if (not get_thumbnails) else 'thumbnail'))
    find_args = {'sort': sort}
    if (maxresults > 0):
        find_args.update({'skip': start, 'limit': maxresults})
    if filter_params:
        query.update(filter_params)
    items = self.fs_files.find(query, **find_args)
    count = items.count()
    assets = list(items)
    for asset in assets:
        asset_id = asset.get('content_son', asset['_id'])
        asset['asset_key'] = course_key.make_asset_key(asset_id['category'], asset_id['name'])
    return (assets, count)
