How to use the twython.oauth.OAuthError function in twython

def _get_version(self, oauth_request):
        try:
            version = oauth_request.get_parameter('oauth_version')
        except:
            version = VERSION
        if version and version != self.version:
            raise OAuthError('OAuth version %s not supported.' % str(version))
        return version

def _check_nonce(self, consumer, token, nonce):
        # verify that the nonce is uniqueish
        nonce = self.data_store.lookup_nonce(consumer, token, nonce)
        if nonce:
            raise OAuthError('Nonce already used: %s' % str(nonce))

def _check_signature(self, oauth_request, consumer, token):
        timestamp, nonce = oauth_request._get_timestamp_nonce()
        self._check_timestamp(timestamp)
        self._check_nonce(consumer, token, nonce)
        signature_method = self._get_signature_method(oauth_request)
        try:
            signature = oauth_request.get_parameter('oauth_signature')
        except:
            raise OAuthError('Missing signature.')
        # validate the signature
        valid_sig = signature_method.check_signature(oauth_request, consumer, token, signature)
        if not valid_sig:
            key, base = signature_method.build_signature_base_string(oauth_request, consumer, token)
            raise OAuthError('Invalid signature. Expected signature base string: %s' % base)
        built = signature_method.build_signature(oauth_request, consumer, token)

def _get_consumer(self, oauth_request):
        consumer_key = oauth_request.get_parameter('oauth_consumer_key')
        if not consumer_key:
            raise OAuthError('Invalid consumer key.')
        consumer = self.data_store.lookup_consumer(consumer_key)
        if not consumer:
            raise OAuthError('Invalid consumer.')
        return consumer

def fetch_request_token(self, oauth_request):
        try:
            # get the request token for authorization
            token = self._get_token(oauth_request, 'request')
        except OAuthError:
            # no token required for the initial token request
            version = self._get_version(oauth_request)
            consumer = self._get_consumer(oauth_request)
            self._check_signature(oauth_request, consumer, None)
            # fetch a new token
            token = self.data_store.fetch_request_token(consumer)
        return token

def _check_signature(self, oauth_request, consumer, token):
        timestamp, nonce = oauth_request._get_timestamp_nonce()
        self._check_timestamp(timestamp)
        self._check_nonce(consumer, token, nonce)
        signature_method = self._get_signature_method(oauth_request)
        try:
            signature = oauth_request.get_parameter('oauth_signature')
        except:
            raise OAuthError('Missing signature.')
        # validate the signature
        valid_sig = signature_method.check_signature(oauth_request, consumer, token, signature)
        if not valid_sig:
            key, base = signature_method.build_signature_base_string(oauth_request, consumer, token)
            raise OAuthError('Invalid signature. Expected signature base string: %s' % base)
        built = signature_method.build_signature(oauth_request, consumer, token)

def _get_signature_method(self, oauth_request):
        try:
            signature_method = oauth_request.get_parameter('oauth_signature_method')
        except:
            signature_method = SIGNATURE_METHOD
        try:
            # get the signature method object
            signature_method = self.signature_methods[signature_method]
        except:
            signature_method_names = ', '.join(self.signature_methods.keys())
            raise OAuthError('Signature method %s not supported try one of the following: %s' % (signature_method, signature_method_names))

        return signature_method

def from_request(http_method, http_url, headers=None, parameters=None, query_string=None):
        # combine multiple parameter sources
        if parameters is None:
            parameters = {}

        # headers
        if headers and 'Authorization' in headers:
            auth_header = headers['Authorization']
            # check that the authorization header is OAuth
            if auth_header.index('OAuth') > -1:
                try:
                    # get the parameters from the header
                    header_params = OAuthRequest._split_header(auth_header)
                    parameters.update(header_params)
                except:
                    raise OAuthError('Unable to parse OAuth parameters from Authorization header.')

        # GET or POST query string
        if query_string:
            query_params = OAuthRequest._split_url_string(query_string)
            parameters.update(query_params)

        # URL parameters
        param_str = urlparse.urlparse(http_url)[4] # query
        url_params = OAuthRequest._split_url_string(param_str)
        parameters.update(url_params)

        if parameters:
            return OAuthRequest(http_method, http_url, parameters)

        return None
    from_request = staticmethod(from_request)