This attempts to find the prompt. Basically, press enter and record
        the response; press enter again and record the response; if the two
        responses are similar then assume we are at the original prompt.
        This can be a slow function. Worst case with the default sync_multiplier
        can take 12 seconds. Low latency connections are more likely to fail
        with a low sync_multiplier. Best case sync time gets worse with a
        high sync multiplier (500 ms with default).

def sync_original_prompt (self, sync_multiplier=1.0):
        '''This attempts to find the prompt. Basically, press enter and record
        the response; press enter again and record the response; if the two
        responses are similar then assume we are at the original prompt.
        This can be a slow function. Worst case with the default sync_multiplier
        can take 12 seconds. Low latency connections are more likely to fail
        with a low sync_multiplier. Best case sync time gets worse with a
        high sync multiplier (500 ms with default). '''
        
        # All of these timing pace values are magic.
        # I came up with these based on what seemed reliable for
        # connecting to a heavily loaded machine I have.
        self.sendline()
        time.sleep(0.1)

        try:
            # Clear the buffer before getting the prompt.
            self.try_read_prompt(sync_multiplier)
        except TIMEOUT:
            pass

        self.sendline()
        x = self.try_read_prompt(sync_multiplier)

        self.sendline()
        a = self.try_read_prompt(sync_multiplier)

        self.sendline()
        b = self.try_read_prompt(sync_multiplier)

        ld = self.levenshtein_distance(a,b)
        len_a = len(a)
        if len_a == 0:
            return False
        if float(ld)/len_a < 0.4:
            return True
        return False