| Java allows methods to declare that they throw checked exceptions even when they |
| don't. This can lead to call sites beng forced to explicitly handle or propagate |
| exceptions which provably can never occur. |
| |
| ```java |
| private static void validateRequest(Request request) throws IOException { |
| checkArgument(request.hasFoo(), "foo must be specified"); |
| } |
| |
| Response handle(Request request) { |
| try { |
| validateRequest(request); |
| } catch (IOException e) { // Required, but unreachable. |
| return failedResponse(); |
| } |
| // ... |
| } |
| ``` |
| |
| Including unthrown exceptions can be reasonable where the method is overridable, |
| as overriding methods will not be able to declare that they throw any exceptions |
| not included. |
