Shanty Mongo连接组

How do I connect to multiple mongodbs dynamically using Shanty_Mongo? According to the docs here: https://github.com/coen-hyde/Shanty-Mongo/wiki/connections

This is how I would write the class

class User extends Shanty_Mongo_Document 
{
    protected static $_connectionGroup = 'users';
}

What if I want to use the same model to write/read to a different database. I cannot set the connectionGroup in a constructor because it is static. How else do I switch between different mongodb using the same model?

add following function in your user class--

public static function _connectionGroup($connectionGroup){
     self::$_connectionGroup = $connectionGroup;
 }

Then call it like user::_connectionGroup("your group");