SampleGraphSort.php

<?php

use \Gliph\Graph\DirectedAdjacencyList;
use \Gliph\Traversal\DepthFirst;

$graph = new DirectedAdjacencyList();

foreach ($entity_list as $entity) {
  if ($entity->has('embedded')) {
    foreach ($entity->get('embedded') as $embedded) {
      $graph->addDirectedEdge($entity, $embedded);
    }
  }
}

if ($cycles = $graph->getCycles()) {
  throw new NaughtyCycleException(sprintf('BAAAAAD here are your cycles: %s', print_r($cycles, TRUE)));
}

$tsl = DepthFirst::toposort($graph);

foreach($tsl as $entity) {
  // do your import thang
}