public function getDefinitionHypercubes()
	{
		if ( $this->hypercubesCache !== null ) return $this->hypercubesCache;

		$hypercubes = array();

		foreach ( $this->getDefinitionRoleRefs() as $roleRefsKey => $role )
		{
			$hypercubes += $this->getDefinitionRoleHypercubes( $roleRefsKey );
		}

		$this->hypercubesCache = $hypercubes;
		return $hypercubes;
	}