public Trailer createTrailer() {
        final Trailer trailer = new Trailer(getRoot(), "Trailer");
        getRoot().insert(trailer);
        return trailer;
    }
public Trailer createTrailer ( ) { final Trailer trailer = new Trailer ( getRoot ( ) , "Trailer" ) ; getRoot ( ) . insert ( trailer ) ; return trailer ; }
Create a trailer for the data set.

@return the created trailer