Why widening generic method parameter counts as major API change?

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Hi,

inspired by a discussion of major API change in Javaslang library (https://gist.github.com/danieldietrich/fbc4121908782ef0314e3f876b392833), I checked, and the case is also valid in currend BND/Bndtools.

When one has an interface:

package test.bundle;

import java.util.List;

public interface TestBundle {
    <T> T foo(List<T> list);
}

widening the list parameter type to List<? extends T> causes Bndtools to claim that the major API change occurs in test.bundle package.

What is the case when this is really the major API change? Specifically, the binary compatibility is kept due to type erasure.

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