Neos\Flow\Package\PackageManager::getFrozenPackages PHP Method

    public function getFrozenPackages()
    {
        $frozenPackages = [];
        if ($this->bootstrap->getContext()->isDevelopment()) {
            /** @var PackageInterface $package */
            foreach ($this->packages as $packageKey => $package) {
                if (isset($this->packageStatesConfiguration['packages'][$package->getComposerName()]['frozen']) && $this->packageStatesConfiguration['packages'][$package->getComposerName()]['frozen'] === true) {
                    $frozenPackages[$packageKey] = $package;
                }
            }
        }
        return $frozenPackages;
    }