private function activate_license_on_many_installs(
            FS_User $user,
            $license_key,
            array $blog_2_install_map
        ) {
            $params = array(
                array( 'license_key' => $this->apply_filters( 'license_key', $license_key ) )
            );

            $install_2_blog_map = array();
            foreach ( $blog_2_install_map as $blog_id => $install ) {
                $params[] = array( 'id' => $install->id );

                $install_2_blog_map[ $install->id ] = $blog_id;
            }

            $result = $this->get_api_user_scope_by_user( $user )->call(
                "plugins/{$this->_plugin->id}/installs.json",
                'PUT',
                $params
            );

            if ( ! $this->is_api_result_object( $result, 'installs' ) ) {
                return $result;
            }

            foreach ( $result->installs as $r_install ) {
                $install                  = new FS_Site( $r_install );
                $install->is_disconnected = false;

                // Update install.
                $this->_store_site(
                    true,
                    $install_2_blog_map[ $r_install->id ],
                    $install
                );
            }

            return true;
        }