Replace a QVector for the wordlist with a QSet. This removes all duplicate entries in a given wordlist.
Thus, it hinders a malicious wordlist that has the proper length (>4000 entries) but with repetitions (effectively << 4000 entries) to be used and potentially create weaker passphrases than estimated.
Example:
List with 4000 items but only 64 unique words would lead to only 48 bit of Entropy instead of ~95 bit!
