(*next)->set_position (c->position ());
c->set_position (c->position() + c->length_after_trim ());
sort (_content.begin(), _content.end(), ContentSorter ());
(*next)->set_position (c->position ());
c->set_position (c->position() + c->length_after_trim ());
sort (_content.begin(), _content.end(), ContentSorter ());