How to use the handprint.network.net function in handprint

(image, error) = self._image_from_file(path)
        if error:
            return error

        base_url = 'https://westus.api.cognitive.microsoft.com/vision/v2.0/'
        url = base_url + 'recognizeText'
        params  = {'mode': 'Handwritten'}
        headers = {'Ocp-Apim-Subscription-Key': self._credentials,
                   'Content-Type': 'application/octet-stream'}

        # The Microsoft API for extracting text requires two phases: one call
        # to submit the image for processing, then polling to wait until the
        # text is ready to be retrieved.

        if __debug__: log('sending file to MS cloud service')
        response, error = net('post', url, headers = headers, params = params, data = image)
        if isinstance(error, NetworkFailure):
            if __debug__: log('network exception: {}', str(error))
            return TRResult(path = path, data = {}, text = '', error = str(error))
        elif isinstance(error, RateLimitExceeded):
            # https://docs.microsoft.com/en-us/azure/azure-resource-manager/resource-manager-request-limits
            # The headers should have a Retry-After number in seconds.
            sleep_time = 30
            if 'Retry-After' in response.headers:
                sleep_time = int(response.headers['Retry-After'])
            if __debug__: log('sleeping for {} s and retrying', sleep_time)
            sleep(sleep_time)
            return self.result(path)    # Recursive invocation
        elif error:
            raise error

        if 'Operation-Location' in response.headers:

if 'Operation-Location' in response.headers:
            polling_url = response.headers['Operation-Location']
        else:
            if __debug__: log('no operation-location in response headers')
            raise ServiceFailure('Unexpected response from Microsoft server')

        if __debug__: log('polling MS for results ...')
        analysis = {}
        poll = True
        while poll:
            # I never have seen results returned in 1 second, and meanwhile
            # the repeated polling counts against your rate limit.  So, wait
            # for 2 s to reduce the number of calls.
            sleep(2)
            response, error = net('get', polling_url, polling = True, headers = headers)
            if isinstance(error, NetworkFailure):
                if __debug__: log('network exception: {}', str(error))
                return TRResult(path = path, data = {}, text = '', error = str(error))
            elif isinstance(error, RateLimitExceeded):
                # Pause to let the server reset its timers.  It seems that MS
                # doesn't send back a Retry-After header when rated limited
                # during polling, but I'm going to check it anyway, in case.
                sleep_time = 30
                if 'Retry-After' in response.headers:
                    sleep_time = int(response.headers['Retry-After'])
                if __debug__: log('sleeping for {} s and retrying', sleep_time)
                sleep(sleep_time)
            elif error:
                raise error

            # Sometimes the response comes back without content.  I don't know

if len(image) > self.max_size():
            text = 'File exceeds {} byte limit for Microsoft service'.format(self.max_size())
            return TRResult(path = path, data = {}, text = '', error = text)

        base_url = 'https://westus.api.cognitive.microsoft.com/vision/v2.0/'
        url = base_url + 'recognizeText'
        params  = {'mode': 'Handwritten'}
        headers = {'Ocp-Apim-Subscription-Key': self._credentials,
                   'Content-Type': 'application/octet-stream'}

        # The Microsoft API for extracting text requires two phases: one call
        # to submit the image for processing, then polling to wait until the
        # text is ready to be retrieved.

        if __debug__: log('Sending file to MS cloud service')
        response, error = net('post', url, headers = headers, params = params, data = image)
        if isinstance(error, NetworkFailure):
            if __debug__: log('Network exception: {}', str(error))
            return TRResult(path = path, data = {}, text = '', error = str(error))
        elif isinstance(error, RateLimitExceeded):
            # https://docs.microsoft.com/en-us/azure/azure-resource-manager/resource-manager-request-limits
            # The headers should have a Retry-After number in seconds.
            sleep_time = 30
            if 'Retry-After' in response.headers:
                sleep_time = int(response.headers['Retry-After'])
            if __debug__: log('Sleeping for {} s and retrying', sleep_time)
            sleep(sleep_time)
            return self.result(path)    # Recursive invocation
        elif error:
            raise error

        if 'Operation-Location' in response.headers:

if 'Operation-Location' in response.headers:
            polling_url = response.headers['Operation-Location']
        else:
            if __debug__: log('No operation-location in response headers')
            raise ServiceFailure('Unexpected response from Microsoft server')

        if __debug__: log('Polling MS for results ...')
        analysis = {}
        poll = True
        while poll:
            # I never have seen results returned in 1 second, and meanwhile
            # the repeated polling counts against your rate limit.  So, wait
            # for 2 s to reduce the number of calls.
            sleep(2)
            response, error = net('get', polling_url, polling = True, headers = headers)
            if isinstance(error, NetworkFailure):
                if __debug__: log('Network exception: {}', str(error))
                return TRResult(path = path, data = {}, text = '', error = str(error))
            elif isinstance(error, RateLimitExceeded):
                # Pause to let the server reset its timers.  It seems that MS
                # doesn't send back a Retry-After header when rated limited
                # during polling, but I'm going to check it anyway, in case.
                sleep_time = 30
                if 'Retry-After' in response.headers:
                    sleep_time = int(response.headers['Retry-After'])
                if __debug__: log('Sleeping for {} s and retrying', sleep_time)
                sleep(sleep_time)
            elif error:
                raise error

            # Sometimes the response comes back without content.  I don't know