Macro redis_command 

macro_rules! redis_command {
    ($ctx:expr,
     $command_name:expr,
     $command_handler:expr,
     $command_flags:expr,
     $firstkey:expr,
     $lastkey:expr,
     $keystep:expr,
     $mandatory_acl_categories:expr
     $(, $optional_acl_categories:expr)?
    ) => { ... };
}