@Nullable
    public T orElse(@Nullable T other) {
        return isPresent() ? this.value : other;
    }
Return the value if present, otherwise return {@code other}.

@param other the value to be returned if there is no value present, may
be null
@return the value, if present, otherwise {@code other}
helper/src/main/java/me/lucko/helper/utils/NullableOptional.java