def _Exec(self, cmd, raise_on_error=True, return_output=False,
            mute_stderr=False):
    self.logger.debug('Running command: %s', cmd)
    stderr = subprocess.PIPE if mute_stderr else None
    p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=stderr)
    (stdoutdata, _) = p.communicate()
    if raise_on_error and p.returncode:
      raise CommandException("Received non-zero return code (%d) from "
                             "subprocess '%s'." % (p.returncode, ' '.join(cmd)))
    return stdoutdata if return_output else p.returncode
@param mailhost: A C{str} giving the mail exchange host which will
dataset/ETHPy150Open GoogleCloudPlatform/gsutil/gslib/commands/perfdiag.py/PerfDiagCommand._Exec--crossover with--dataset/ETHPy150Open kuri65536/python-for-android/python-modules/twisted/twisted/news/database.py/NewsShelf.__init__