def get_connection(database_name):
    """Return a Connection for the named database.

        This is intended to be called from an open Connection associated with
        a multi-database.  In that case, database_name must be the name of a
        database within the database collection (probably the name of a
        different database than is associated with the calling Connection
        instance, but it's fine to use the name of the calling Connection
        object's database).  A Connection for the named database is
        returned.  If no connection to that database is already open, a new
        Connection is opened.  So long as the multi-database remains open,
        passing the same name to get_connection() multiple times returns the
        same Connection object each time.
        """
