A magistrates' court shall not exercise its power under section 76 above to issue a warrant to commit to prison a person who makes default in paying a sum adjudged to be paid by an order of such a court except where the default is under—
This section does not affect the power of a magistrates' court to issue such a warrant as aforesaid in the case of default in paying a sum adjudged to be paid by a conviction, or treated (by any enactment relating to the collection or enforcement of fines, costs, compensation or forfeited recognizances) as so adjudged to be paid.
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