parameters: (self, _, tab)
docstring: Start the per-page preparation for this metric.
  
      Here, this consists of recording the start value.
docstring_summary: Start the per-page preparation for this metric.
docstring_tokens: Start the per - page preparation for this metric .
function: def Start(self, _, tab):
      """Start the per-page preparation for this metric.
  
      Here, this consists of recording the start value.
      """
      self._browser = tab.browser
      if not self._platform.CanMonitorNetworkData():
        return
  
      data = self._platform.GetNetworkData(self._browser)
      if data is not None:
        self._network_snd, self._network_rcv = data
function_tokens: def Start ( self , _ , tab ) : self . _browser = tab . browser if not self . _platform . CanMonitorNetworkData ( ) : return data = self . _platform . GetNetworkData ( self . _browser ) if data is not None : self . _network_snd , self . _network_rcv = data