This function parses the `--marking_json` and `--marking_pfill` arguments
        and creates a marking object if these parameters are specified.

        Look into 'dingos/management/commands/dingos_generic_xml_import.py to see how
        this is used to specify a Django command line argument 'dingos_generic_xml_import'
        that can be called with Django's 'manage.py'

def create_import_marking(self, args, options):
        """
        This function parses the `--marking_json` and `--marking_pfill` arguments
        and creates a marking object if these parameters are specified.

        Look into 'dingos/management/commands/dingos_generic_xml_import.py to see how
        this is used to specify a Django command line argument 'dingos_generic_xml_import'
        that can be called with Django's 'manage.py'
        """
        marking_json = None
        placeholder_dict = {}

        if options.get('marking_json'):
            # Open json
            with open(options['marking_json'], 'r') as content_file:
                marking_json = content_file.read()

            del(options['marking_json'])

            # Find all placeholders
            placeholders = self.RE_SEARCH_PLACEHOLDERS.findall(marking_json)

            # Create prefilled dictionary so that later when we use
            # the json text as format string we do not encounter problems
            # for undefined placeholders.

            if placeholders:

                for placeholder in placeholders:
                    placeholder_dict[placeholder] = 'EMPTY'

        # Read in command-line specified placeholder values.
        if options.get('placeholder_fillers'):
            for (placeholder, value) in options['placeholder_fillers']:
                placeholder_dict[placeholder] = value

            del(options['placeholder_fillers'])

        # Add standard values (this list may grow in future)
        placeholder_dict['_username'] = getpass.getuser()
        placeholder_dict['_command'] = os.path.basename(__file__)
        placeholder_dict['_kargs'] = "%s" % options
        placeholder_dict['_args'] = args

        if marking_json:
            # Massage the json text such that we can use it as format string
            # to fill in the placeholders

            # Escape possible '%'
            marking_json = marking_json.replace('%','\%')
            # Replace placeholder definitions with python string formatting
            marking_json = self.RE_SEARCH_PLACEHOLDERS.sub("%(\\1)s", marking_json)

            # Use string formatting to fill in placeholders

            marking_json = marking_json % placeholder_dict

            # Finally, parse json
            marking_dict = dict2DingoObjDict(json.loads(marking_json))

            # Create info object for marking
            marking = DingoImporter.create_marking_iobject(metadata_dict=marking_dict)

            return marking

        return None