def for_host(parent, host):
        """
        Returns a new AccountProxy that has an account acquired. The
        account is chosen based on what the connected AccountManager
        selects for the given host.
        """
        account = AccountProxy(parent)
        account.host = host
        if account.acquire():
            return account
        return None
Returns a new AccountProxy that has an account acquired. The
        account is chosen based on what the connected AccountManager
        selects for the given host.