return this.inDfs;
    }

    /**
     *
     */
    void markDomainDfs() {
        this.inDomainDfs = true;
    }

    /**
     * @return whether this tree was accessed using domain DFS
     */
    public boolean isInDomainDfs() {
        return this.inDomainDfs;
    }

    /**
     * @param referral
     */
    public void setTreeReferral(final DfsReferralData referral) {