Whenever it is set forth in the petition that there are unknown owners, or unknown heirs, devisees, or legatees of deceased owners, who claim or appear to have some interest in, rights or title to, or lien upon the real estate sought to be leased, the provisions of section 25-321 shall be followed before authority to execute a lease or pooling or unitization contract may be granted. To carry out the provisions of sections 57-210 to 57-212.01, the court may, upon the hearing of the petition, appoint a trustee to represent the interests of such unknown owners, or unknown heirs, devisees, or legatees and to carry out the orders of the court with respect thereto.