* Memformer A3:
    * Memformer paper's architecture
        * Use memory itself to generate queries
    * Add zero memory init
    * Add extract (prompt) tokens
* Memformer A4:
    * One training head 
* Memformer B3:
    * newer structure
        * Has a fixed query to query memory states
    * Add zero memory init
    * Add extract (prompt) tokens
* Memformer B4:
    * B3 structure but add 