> The only truly unforgiveable one is UnsupportedOperationException. The guy who wrote the collections API for Java didn't know the first thing about the Liskov

> The only truly unforgiveable one is UnsupportedOperationException. The guy who wrote the collections API for Java didn't know the first thing about the Liskov Substitution Principle, and gave the world an implementation that violates it... The implementation perfectly follows it because the LSP simply requires identical behavior, and the contract clearly states it may[1] throw an exception. All the implementations "may" throw an exception. Sorry, but they correctly lawyered the LSP. > I came up with around 20% more than the selected design. But `add` can throw 5 different exceptions depending on restrictions your implementation wants to place on a given collection, does it allow for all that? In terms of making an interface that was small and reusable by many projects, runtime exceptions are a pretty good compromise for a standard library. [1]: https://docs.oracle.com/javase/7/docs/api/java/util/Collection.html#add(E) https://docs.oracle.com/javase/7/docs/api/java/util/Collecti...