Platformsh\Cli\Command\Environment\EnvironmentListCommand::buildEnvironmentTree PHP Method

    protected function buildEnvironmentTree(array $environments, $parent = null)
    {
        $children = [];
        foreach ($environments as $environment) {
            if ($environment->parent === $parent) {
                $this->children[$environment->id] = $this->buildEnvironmentTree($environments, $environment->id);
                $children[$environment->id] = $environment;
            }
        }
        return $children;
    }