function storeAssociation($server_url, $association)
    {
        // create memcached keys for association itself
        // and list of associations for this server
        $associationKey = $this->associationKey($server_url,
            $association->handle);
        $serverKey = $this->associationServerKey($server_url);

        // get list of associations
        $serverAssociations = $this->connection->get($serverKey);

        // if no such list, initialize it with empty array
        if (!$serverAssociations) {
            $serverAssociations = array();
        }
        // and store given association key in it
        $serverAssociations[$association->issued] = $associationKey;

        // save associations' keys list
        $this->connection->set(
            $serverKey,
            $serverAssociations,
            $this->compress
        );
        // save association itself
        $this->connection->set(
            $associationKey,
            $association,
            $this->compress,
            $association->issued + $association->lifetime);
    }