code: @SafeVarargs
      public final Builder retryOn(Class<? extends Exception>... exceptions) {
        for (Class<? extends Exception> exception : exceptions) {
          retriableExceptions.add(checkNotNull(exception));
        }
        return this;
      }
docs: Add the exceptions to ignore/retry-on.
  
  @param exceptions retry should continue when such exceptions are thrown
  @return the Builder for chaining