code: def sudoers(self, enable):
          
          f_sudoers = "/isan/vdc_1/virtual-instance/guestshell+/rootfs/etc/sudoers"
  
          if enable is True:
              sed_cmd = r" 's/\(^Defaults *requiretty\)/#\1/g' "
          elif enable is False:
              sed_cmd = r" 's/^#\(Defaults *requiretty\)/\1/g' "
          else:
              raise RuntimeError('enable must be True or False')
  
          self.guestshell("run bash sudo sed -i" + sed_cmd + f_sudoers)
docs: This method is used to enable/disable bash sudo commands running
          through the guestshell virtual service.  By default sudo access
          is prevented due to the setting in the 'sudoers' file.  Therefore
          the setting must be disabled in the file to enable sudo commands.
  
          This method assumes that the "bash-shell" feature is enabled.
          @@@ TO-DO: have a mech to check &| control bash-shell feature support
  
          :param enable:
              True - enables sudo commands
              False - disables sudo commands
  
          :return:
              returns the response of the sed command needed to make the
              file change