def METHOD_NAME(input_filename, **kwargs):
    """Main calling subroutine for the ``runsinglehap`` task.
    Parameters
    ----------
    input_filename : str
        Name of the input csv file containing information about the files to
        be processed
    debug : bool, optional
        display all tracebacks, and debug information? If not specified, the default value is Boolean 'False'.
    input_custom_pars_file : str, optional
        Represents a fully specified input filename of a configuration JSON file which has been
        customized for specialized processing. This file should contain ALL the input parameters necessary
        for processing. If not specified, default configuration parameter values will be used.
    log_level : str, optional
        The desired level of verboseness in the log statements displayed on the screen and written to the
        .log file. Valid inputs: 'critical', 'error', 'warning', 'info', or 'debug'. If not specified, the
        default value is 'info'.
    Updates
    -------
    return_value : list
        a simple status value. '0' for a successful run and '1' for a failed run
    """
    # set up log_level as an input to hapsequencer.run_hap_processing().
    log_level_dict = {"critical": logutil.logging.CRITICAL,
                      "error": logutil.logging.ERROR,
                      "warning": logutil.logging.WARNING,
                      "info": logutil.logging.INFO,
                      "debug": logutil.logging.DEBUG}
    if 'log_level' in kwargs:
        kwargs['log_level'] = kwargs['log_level'].lower()
        if kwargs['log_level'] in log_level_dict.keys():
            kwargs['log_level'] = log_level_dict[kwargs['log_level']]
        else:
            print("Log level set to default level 'log.info'.")
            kwargs['log_level'] = logutil.logging.INFO
    else:
        print("Log level set to default level 'log.info'.")
        kwargs['log_level'] = logutil.logging.INFO
    # execute hapsequencer.run_hap_processing()
    return_value = hapsequencer.run_hap_processing(input_filename, **kwargs)
    return return_value