Klever

Currently Klever filters options of CC commands before they are passed further to CIF. It employs the "black list" method of filtering, where unsupported options are explicitly listed and filtered. On the other hand, Clade employs the "white list" method of filtering, in which only the options required by CIF are explicitly listed, while all other options are filtered.

Usage of "white list" in Clade is proved to be far easier to support and generally superior than "black list". So, it's time to use it in Klever as well, and the simplest way to do it is to import and use the Clade implementation directly.

In future, however, it is expected that this functionality will become a part of the CIF Python interface (https://forge.ispras.ru/issues/6780).