human
Solve the following python programming problem given the following code:
def _Cmd(self, command, mode = None) : 
    def SendAndWait(command) : 
        'Sends a command and waits for a response.' 
        self._connection.child.send ((command + '\r')) 
        self._connection.child.expect ('\r
', timeout = self.timeout_response) 
        self._connection.child.expect (self._connection.re_prompt, timeout = self.timeout_response, searchwindowsize = 128) 
        return self._connection.child.before.replace ('\r
', os.linesep) 
_ = mode 
    command = command.replace ('?', '') 
    result = '' 
    try : 
        result = SendAndWait (command) 
except pexpect.TIMEOUT as e : 
        self.connected = False 
        raise exceptions.CmdError (('%s: %s' % (e.__class__, str (e)))) 
except pexpect.EOF : 
        try : 
            self.connected = False 
            self._connection.Connect () 
            self._DisablePager () 
            self.connected = True 
            result = SendAndWait (command) 
except pexpect.EOF : 
            raise exceptions.CmdError ('Failed with EOF error twice.') 
except pexpect_connection.ConnectionError as e : 
            raise exceptions.CmdError (('Auto-reconnect failed: %s' % e)) 
except pexpect_connection.TimeoutError as e : 
            raise exceptions.CmdError (('Auto-reconnect timed out: %s' % e)) 
if (result and (result [(- 1)] == '\r')) : 
        result = (result [: (- 1)] + '
') 
if (result.endswith (INVALID_OUT1) or result.startswith (INVALID_OUT2)) : 
        raise exceptions.CmdError (('Command failed: %s' % self)) 
return result 

    
    

    Fix the buggy line: raise exceptions.CmdError (('Command failed: %s' % self))
assistant
#Here is Python code to fix the buggy line: raise exceptions.

raise exceptions.CmdError (('Command failed: %s' % result))