code: def trace_region(self, region_index):
          
          cmd = enums.JLinkTraceCommand.GET_REGION_PROPS_EX
          region = structs.JLinkTraceRegion()
          region.RegionIndex = int(region_index)
          res = self._dll.JLINKARM_TRACE_Control(cmd, ctypes.byref(region))
          if (res == 1):
              raise errors.JLinkException('Failed to get trace region.')
          return region
docs: Retrieves the properties of a trace region.
  
          Args:
            self (JLink): the ``JLink`` instance.
            region_index (int): the trace region index.
  
          Returns:
            An instance of ``JLinkTraceRegion`` describing the specified region.