Upon the presentation of the petition and affidavit, with due proof, by affidavit, of service of a copy thereof, and of the notice, if sufficient cause to the contrary is not shown by the adverse party, the court must either issue a commission, as prescribed in the following sections of this article or make an order, directing the adverse party, at a time and place therein specified, before the court, or a referee therein designated, to produce the person upon whose life the prior estate depends, or, in default thereof, to prove that he is living.
New York Legal Code