code: def _notifications(self):
          
          if not self.username or not self.auth_token:
              if not self.notification_warning:
                  self.py3.notify_user(
                      "Github module needs username and "
                      "auth_token to check notifications."
                  )
                  self.notification_warning = True
              return "?"
          if self.notifications == "all" or not self.repo:
              url = self.url_api + "/notifications"
          else:
              url = self.url_api + "/repos/" + self.repo + "/notifications"
          url += "?per_page=100"
          try:
              info = self.py3.request(url, auth=(self.username, self.auth_token))
          except (self.py3.RequestException):
              return
          if info.status_code == 200:
              links = info.headers.get("Link")
  
              if not links:
                  return len(info.json())
  
              last_page = 1
              for link in links.split(","):
                  if 'rel="last"' in link:
                      last_url = link[link.find("<") + 1 : link.find(">")]
                      parsed = urlparse.urlparse(last_url)
                      last_page = int(urlparse.parse_qs(parsed.query)["page"][0])
  
              if last_page == 1:
                  return len(info.json())
              try:
                  last_page_info = self.py3.request(
                      last_url, auth=(self.username, self.auth_token)
                  )
              except self.py3.RequestException:
                  return
  
              return len(info.json()) * (last_page - 1) + len(last_page_info.json())
  
          if info.status_code == 404:
              if not self.repo_warning:
                  self.py3.notify_user("Github repo cannot be found.")
                  self.repo_warning = True
docs: Get the number of unread notifications.