code: def _start_ubridge_capture(self, adapter_number, output_file):
          
  
          vnet = "ethernet{}.vnet".format(adapter_number)
          if vnet not in self._vmx_pairs:
              raise VMwareError("vnet {} not in VMX file".format(vnet))
          if not self._ubridge_hypervisor:
              raise VMwareError("Cannot start the packet capture: uBridge is not running")
          yield from self._ubridge_send('bridge start_capture {name} "{output_file}"'.format(name=vnet,
                                                                                             output_file=output_file))
docs: Start a packet capture in uBridge.
  
          :param adapter_number: adapter number
          :param output_file: PCAP destination file for the capture