'This method is used to test if the transfer method works as expected.
The implementation of this should transfer 10 bytes and check if they
arrived as expected to the other end.'

def can_transfer(self):

    for fetcher in ['wget', 'curl', 'lynx']:
        res = self._exec_method(('which    ' + fetcher))
        if res.startswith('/'):
            self._command = fetcher
            try:
                return self.transfer('test_string\n', get_remote_temp_file(self._exec_method))
            except:
                continue
    return False
