docs: async def _get_usage_data(self):
          """Get data usage."""
          # Get Usage
          raw_res = await self._session.get(USAGE_URL)
          content = await raw_res.text()
          soup = BeautifulSoup(content, 'html.parser')
          # Find all span
          span_list = soup.find_all("span", {"class": "switchDisplay"})
          if span_list is None:
              raise PyEboxError("Can not get usage page")
          usage_data = {}
          # Get data
          for key, index in USAGE_MAP.items():
              try:
                  str_value = span_list[index].attrs.get("data-m").split()[0]
                  usage_data[key] = abs(float(str_value)) / 1024
              except OSError:
                  raise PyEboxError("Can not get %s", key)
          return usage_data