in debug log, there is a line state that:

[CryptRand] 0 bytes of randomness leftover in the buffer.

I have searched about this line but not much helpful information available.

The only information I found for CryptRand is https://www.mediawiki.org/wiki/Manual:CryptRand.php .

The MWCryptRand class is a cryptographic random generator class used for generating secret keys. This is based in part on Drupal code as well as what we used in our own code prior to introduction of this class.

Is the "0 bytes of randomness leftover" a severe problem? Do we need to fix it?