A more thorough explanation:

The presumed-seller test is a way of holding a manufacturer responsible for any harm caused by their product if they knew about its dangerous qualities and still decided to sell it. This means that if a manufacturer is aware of a potential danger associated with their product, they have a duty to warn consumers about it or take steps to make the product safer.

For example, let's say a company manufactures a toy that has small parts that could be a choking hazard for young children. If the company is aware of this danger but fails to include a warning on the packaging or take steps to make the toy safer, they could be held liable if a child chokes on the toy.

Another example could be a car manufacturer that knows about a defect in their vehicles that could cause the brakes to fail. If they continue to sell the cars without fixing the defect or warning consumers about it, they could be held responsible for any accidents or injuries that result from the brake failure.

These examples illustrate how the presumed-seller test works by holding manufacturers accountable for the safety of their products. It ensures that companies cannot simply ignore potential dangers associated with their products and must take steps to protect consumers from harm.