§ 102. Undertaking to accompany application for discharge. The application shall be accompanied by an undertaking to the lienor executed by at least two sureties in a sum at least twice the amount specified in the warrant, to the effect that the person making the application for the discharge of the vessel will pay the amount of all claims and demands which shall be established to be due to the person in whose behalf the warrant was issued, and to have been a subsisting lien on the vessel at the time of its issue. The undertaking when found sufficient, must be approved by the justice to whom the application is made as to the sufficiency of the sureties, and the lienor may examine the sureties as to their sufficiency at such time and places as may be fixed by such justice.