code: public function expand($edges = [], $force = false)
  	{
  		if ($force)	foreach ($this->models as $i => $model) $this->models[$i]->expand($edges);
  		else		foreach ($this->models as $i => $model) if (is_a($model, "SnooPHP\Model\Node")) $this->models[$i]->expand($edges);
  		return $this;
  	}
docs: Expands nodes within this collection
  
  @param string|array	$edges	edges to expand
  @param bool			$force	if true assumes all models are nodes
  
  @return static return this collection