code: protected final <O extends AbstractOption<V>, V> V getOrElse0(O option, V defaultValue) {
          return get0(option).orElse(defaultValue);
      }
docs: Returns the value of the specified {@code option}.
  
  @param <O> the type of the option
  @param <V> the type of the value
  @return the value of the specified {@code option}. {@code defaultValue} if there's no such option.