Bug: data present in web interface missing from API response

[Matt]

For some books, the edition language is correct in the web interface, but the language_code element in the API results for that book is unset.

An example: https://www.goodreads.com/book/show/5... shows an Edition Language of English. However,

"""
gr_key=[% key %]

get_gr_book() {
book_id=$1
gr_xml=$(curl -s https://www.goodreads.com/book/show/$...)
echo -n 'Author: '; echo "$gr_xml" | xml_grep --text_only //GoodreadsResponse/book/authors/author[0]/name
echo -n 'Title: '; echo "$gr_xml" | xml_grep --text_only //GoodreadsResponse/book/title
echo -n 'Language: '; echo "$gr_xml" | xml_grep --text_only //GoodreadsResponse/book/language_code
echo
}

$ get_gr_book 5968469
Author: Agnes Owens
Title: The Complete Short Stories
Language:

$
"""

This does, however, work with other books:

"""
$ get_gr_book 366649
Author: Émile Zola
Title: Le Ventre de Paris (Les Rougon-Macquart, #3)
Language: fre

$
"""