The justification of sureties mentioned in section 574.01 shall be by affidavit, annexed to the bond or other security, wherein each surety shall state, under oath, that it is worth a certain definite amount above its debts and liabilities and exclusive of its property exempt from execution, but the aggregate of the amount sworn to as aforesaid by all the sureties shall be not less than double the amount of the penalty of such bond or other security. Where in the cases provided by law exception is taken to sureties, they shall be examined by the judge or officer before whom they are required to attend for purposes of justification, in such manner as the judge or officer shall deem proper. The examination shall be reduced to writing and filed in the cause and, on deeming the sureties sufficient, the judge or officer shall endorse approval upon the instrument, and return the same to the proper custodian thereof.