code: private static function updateRecursion($document)
  	{
  		$result = array();
  		foreach (self::toDotted($document, '', 1) as $path => $value) {
  			$result[] = $path . $value;
  		}
  
  		return implode(' ', $result);
  	}
docs: Parse document for valid update command.
  
  @param  mixed  $document
  @return string