private function getMessages( $arcRole, $lang = null )
	{
		$arcs = $this->xbrlTaxonomy->getGenericArc( $arcRole, $this->extendedLinkRoleUri, $this->label, $this->path, null, $this->linkbase );

		$messages = array();

		foreach ( $arcs as $arc )
		{
			if ( $arc['frompath'] != $this->path ) continue;

			$this->xbrlTaxonomy->getGenericResource( 'message', 'message', function( $roleUri, $linkbase, $variableSetName, $index, $resource ) use( &$messages, $arc, $lang )
			{
				// BMS 2019-02-11

				// if ( $resource['label'] != $arc['to'] ) return true;
				if ( $resource['path'] != $arc['topath'] /* || $linkbase != $arc['linkbase'] */ ) return true;
				if ( ! is_null( $lang ) )
				{
					if ( $resource['lang'] != $lang && $resource['lang'] != strstr( $lang, "-", true ) )
					{
						return true;
					}
				}

				$messages[ $arc['to'] ] = $resource['message'];

				return true;
			}, $arc['toRoleUri'], $arc['to'], $arc['tolinkbase'] );
		}

		return $messages;
	}