'Find all structures that specified in `ids`. Among the blocks only return block whose type is `course`.
Arguments:
ids (list): A list of structure ids'

@autoretry_read()
def find_course_blocks_by_id(self, ids, course_context=None):

    with TIMER.timer('find_course_blocks_by_id', course_context) as tagger:
        tagger.measure('requested_ids', len(ids))
        docs = [structure_from_mongo(structure, course_context) for structure in self.structures.find({'_id': {'$in': ids}}, {'blocks': {'$elemMatch': {'block_type': 'course'}}, 'root': 1})]
        tagger.measure('structures', len(docs))
        return docs
