Throwable is thrown from inside a catch block. The originally caught Exception will be chained to the new Throwable via this field.
Throwable.next
inout(Throwable) next() @property @trusted inout return scope pure nothrow @nogcReturns
A reference to the _next error in the list. This is used when a new
void next(Throwable tail) @property @trusted scope pure nothrow @nogcReplace next in chain with tail. Use chainTogether instead if at all possible.