private function sync_license_if_not_exist( $license_id, $license_key ) {
            $license = $this->_get_license_by_id( $license_id );

            if ( is_object( $license ) ) {
                // License already exists.
                return $license;
            }

            $license = $this->fetch_license_by_key( $license_id, $license_key );

            if ( $license instanceof FS_Plugin_License ) {
                $this->_licenses[] = $license;
                $this->_license    = $license;
                $this->_store_licenses();

                return $license;
            }

            return $license;
        }