LazyValue example

$file = $this->files[$id] ??= $this->getFile($id);

                    if (isset(self::$valuesCache[$file])) {
                        [$expiresAt, $this->values[$id]] = self::$valuesCache[$file];
                    } elseif (\is_array($expiresAt = include $file)) {
                        if ($this->appendOnly) {
                            self::$valuesCache[$file] = $expiresAt;
                        }

                        [$expiresAt, $this->values[$id]] = $expiresAt;
                    } elseif ($now < $expiresAt) {
                        $this->values[$id] = new LazyValue($file);
                    }

                    if ($now >= $expiresAt) {
                        unset($this->values[$id], $missingIds[$k], self::$valuesCache[$file]);
                    }
                } catch (\ErrorException $e) {
                    unset($missingIds[$k]);
                }
            }
        } finally {
            restore_error_handler();
        }