For the purpose of justification, each of the bail shall attend before the court or judge, at the time and place mentioned in the notice, and may be examined on oath, on the part of the plaintiff, touching his sufficiency, in such manner as the court, or judge, in his discretion, may think proper. The examination must be reduced to writing and subscribed by the bail, if required by the plaintiff. (C.C.P., s. 165; Code, s. 307; Rev., s. 742; C.S., s. 782; 1971, c. 268, s. 27.)