public boolean matchesThrowableTop(Throwable throwable) {
    if (regexes == null) {
      return false;
    }

    return throwableMatchesExpressions(throwable.toString(), regexes);
  }
Whether throwable matches the top-level (ie: most recent, or high-stack-level propogator) of
this stack trace.
portability-types-transfer/src/main/java/org/datatransferproject/types/transfer/retry/RetryMapping.java