def check_output(self, cmd):
ret, output = self._call(cmd, True)<EOL>if ret != <NUM_LIT:0>:  <EOL><INDENT>raise RemoteCommandFailure(command=cmd, ret=ret)<EOL><DEDENT>logger.debug("<STR_LIT>", output)<EOL>return output<EOL>
Calls a command through SSH and returns its output.