<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def download_tar(self, url, untar=True, delete_after_untar=False, destination_dir='.'):
 """ Download and optionally untar the tar file from the given url """

        try:
            floyd_logger.info("Downloading the tar file to the current directory ...")
            filename = self.download(url=url, filename='output.tar')
            if filename and untar:
                floyd_logger.info("Untarring the contents of the file ...")
                tar = tarfile.open(filename)
                tar.extractall(path=destination_dir)
                tar.close()
            if delete_after_untar:
                floyd_logger.info("Cleaning up the tar file ...")
                os.remove(filename)
            return filename
        except FloydException as e:
            floyd_logger.info("Download URL ERROR! {}".format(e.message))
            return False