code: def list_musts(options):
      
      validator_list = [
          timestamp,
          timestamp_compare,
          observable_timestamp_compare,
          object_marking_circular_refs,
          granular_markings_circular_refs,
          marking_selector_syntax,
          observable_object_references,
          artifact_mime_type,
          character_set,
          language,
          software_language,
          patterns,
          language_contents,
      ]
  
      # --strict-types
      if options.strict_types:
          validator_list.append(types_strict)
  
      # --strict-properties
      if options.strict_properties:
          validator_list.append(properties_strict)
  
      return validator_list
docs: Construct the list of 'MUST' validators to be run by the validator.