In Brazil, the duty to mitigate damages derives from the objective good faith ("boa-fé objetiva") doctrine.
There are multiple definitions - click on the translation that matches your context.
the legal requirement that someone who has suffered loss because of another person's breach of contract or negligence must do what they can to minimize or reduce any losses and to prevent these losses from getting worse
The court held that a party is entitled to recover expenses incurred in mitigation of damages.
a defence that may be used to reduce the amount of damages that a defendant in a lawsuit must pay the claimant
Doe did not sufficiently plead mitigation of damages because it was irrelevant as Malibu had elected statutory damages.