code: def open_dut_connections(self):
          
          for dut in self.duts:
              try:
                  dut.start_dut_thread()
                  if hasattr(dut, "command"):
                      dut.open_dut(dut.command)
                  else:
                      dut.open_dut()
              except DutConnectionError:
                  self.logger.exception("Failed when opening dut connection")
                  dut.close_dut(False)
                  dut.close_connection()
                  dut = None
                  raise
docs: Opens connections to Duts. Starts Dut read threads.
  
          :return: Nothing
          :raises DutConnectionError: if problems were encountered while opening dut connection.