/**
  * Calculate's the "size" of a node in the hierachical
  * structure, based off it's left and right limits.
  *
  * @param  Cartalyst\NestedSets\Nodes\NodeInterface  $node
  * @return int
  */
 public function getNodeSize(NodeInterface $node)
 {
     return $node->getAttribute($node->getReservedAttributeName('right')) - $node->getAttribute($node->getReservedAttributeName('left'));
 }
 /**
  * Get the name of a reserved attribute.
  *
  * @param  string  $key
  * @return string
  */
 public function getReservedAttributeName($key)
 {
     return $this->baseNode->getReservedAttributeName($key);
 }