public function getDefinitionDimensions()
	{
		if ( $this->dimensionsCache !== null ) return $this->dimensionsCache;

		$dimensions = array();
		$taxonomy_base_name = $this->getTaxonomyXSD();

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

		$this->dimensionsCache = $dimensions;
		return $dimensions;
	}