public function getContainmentTreeChildren(BaseGenerator $component) {
    $component_id = $this->getComponentKey($component);

    $tree = $this->getContainmentTree();

    $child_ids = $tree[$component_id] ?? [];
    $return = [];
    foreach ($child_ids as $id) {
      $return[$id] = $this->components[$id];
    }

    return $return;
  }