code: def verify_strain_options_multi_ifo(opts, parser, ifos):
      
      for ifo in ifos:
          for opt_group in ensure_one_opt_groups:
              ensure_one_opt_multi_ifo(opts, parser, ifo, opt_group)
          required_opts_multi_ifo(opts, parser, ifo, required_opts_list)
docs: Sanity check provided strain arguments.
  
      Parses the strain data CLI options and verifies that they are consistent
      and reasonable.
  
      Parameters
      ----------
      opt : object
          Result of parsing the CLI with OptionParser, or any object with the
          required attributes (gps-start-time, gps-end-time, strain-high-pass,
          pad-data, sample-rate, frame-cache, channel-name, fake-strain,
          fake-strain-seed).
      parser : object
          OptionParser instance.
      ifos : list of strings
          List of ifos for which to verify options for