// Now merge the data into the Session object.
$changed = false;
- $cache = isset( $this->sessionFieldCache[$id] ) ? $this->sessionFieldCache[$id] : [];
+ $cache = $this->sessionFieldCache[$id] ?? [];
foreach ( $data as $key => $value ) {
if ( !array_key_exists( $key, $cache ) ) {
if ( $session->exists( $key ) ) {