isbn_from_words returns empty string

[PizzaTreeIsland]

isbn_from_words returns a string with a lenght of 0. I tried it with several arguments and famous books, none of them worked.

`import isbnlib

isbn = isbnlib.isbn_from_words("Nineteen Eighty-Four Orwell")
print(isbn)
print(type(isbn))
print(len(isbn))
print(isbnlib.meta(isbn))`

<class 'str'> 0 {}