How to use the goslate.goslate.Error function in goslate

:Example:

         >>> gs = Goslate()
         >>> print(gs.translate('Hello World', 'de'))
         Hallo Welt
         >>>
         >>> for i in gs.translate(['thank', u'you'], 'de'):
         ...     print(i)
         ...
         danke
         Sie

        '''

        if not target_language:
            raise Error('invalid target language')

        if not _is_sequence(text):
            if isinstance(text, unicode):
                text = text.encode('utf-8')
            return self._translate_single_text(text, target_language, source_language)

        JOINT = u'\u26ff'
        UTF8_JOINT = (u'\n%s\n' % JOINT).encode('utf-8')

        def join_texts(texts):
            def convert_to_utf8(texts):
                for i in texts:
                    if isinstance(i, unicode):
                        i = i.encode('utf-8')
                    yield i.strip()

def split_text(text):
            start = 0
            text = quote_plus(text)
            length = len(text)
            while (length - start) > self._MAX_LENGTH_PER_QUERY:
                for seperator in self._SEPERATORS:
                    index = text.rfind(seperator, start, start+self._MAX_LENGTH_PER_QUERY)
                    if index != -1:
                        break
                else:
                    raise Error('input too large')
                end = index + len(seperator)
                yield unquote_plus(text[start:end])
                start = end

            yield unquote_plus(text[start:])

def _basic_translate(self, text, target_language, source_language=''):
        # assert _is_bytes(text)

        if not target_language:
            raise Error('invalid target language')

        if not text.strip():
            return u'', unicode(target_language)

        # Browser request for 'hello world' is:
        # http://translate.google.com/translate_a/t?client=t&hl=en&sl=en&tl=zh-CN&ie=UTF-8&oe=UTF-8&multires=1&prev=conf&psl=en&ptl=en&otf=1&it=sel.2016&ssel=0&tsel=0&prev=enter&oc=3&ssel=0&tsel=0&sc=1&text=hello%20world

        GOOGLE_TRASLATE_URL = 'http://translate.google.com/translate_a/t'
        GOOGLE_TRASLATE_PARAMETERS = {
            # 't' client will receiver non-standard json format
            # change client to something other than 't' to get standard json response
            'client': 'z',
            'sl': source_language,
            'tl': target_language,
            'ie': 'UTF-8',
            'oe': 'UTF-8',

def _open_url(self, url):
        if len(url) > self._MAX_LENGTH_PER_QUERY+100:
            raise Error('input too large')

        # Google forbits urllib2 User-Agent: Python-urllib/2.7
        request = Request(url, headers={'User-Agent':'Mozilla/4.0'})

        exception = None
        # retry when get (, error(54, 'Connection reset by peer')
        for i in range(self._RETRY_TIMES):
            try:
                response = self._opener.open(request, timeout=self._TIMEOUT)
                response_content = response.read().decode('utf-8')
                if self._DEBUG:
                    print(response_content)
                return response_content
            except socket.error as e:
                if self._DEBUG:
                    import threading