spurious "extends Throwable" at end of Optional.orElseThrow method declaration

A DESCRIPTION OF THE PROBLEM :
https://docs.oracle.com/javase/8/docs/api/java/util/Optional.html#orElseThrow-java.util.function.Supplier-
There is a superfluous string of "extends Throwable" at end of method declaration in the above section of the doc.
Also at end of that same section, "X extends Throwable" appears yet again (after "NullPointerException - if no value is present and exceptionSupplier is null"), which is invalid.

REGRESSION : Last worked in version 8

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Look at docs at the above URL, for Java versions 8 through 10 inclusive.


FREQUENCY : always