} elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
$value = array_merge_recursive( $value, $fallbackValue );
} elseif ( in_array( $key, self::$optionalMergeKeys ) ) {
} elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
$value = array_merge_recursive( $value, $fallbackValue );
} elseif ( in_array( $key, self::$optionalMergeKeys ) ) {