def METHOD_NAME(self, filename, filename_info, filetype_info):
    """Mimic reader input file content."""
    dt = filename_info.get('start_time', datetime(2016, 1, 1, 12, 0, 0))
    sat, inst = {
        'VIIRS_NPP': ('NPP', 'VIIRS'),
        'VIIRS_N20': ('N20', 'VIIRS'),
    }[filename_info['sensor_id']]
    file_content = {
        '/attr/platform': sat,
        '/attr/sensor': inst,
        '/attr/spatial_resolution': '742 m at nadir',
        '/attr/time_coverage_start': dt.strftime('%Y%m%dT%H%M%SZ'),
        '/attr/time_coverage_end': (dt + timedelta(minutes=6)).strftime('%Y%m%dT%H%M%SZ'),
    }
    file_content['lat'] = DEFAULT_LAT_DATA
    file_content['lat/attr/comment'] = 'Latitude of retrievals'
    file_content['lat/attr/long_name'] = 'latitude'
    file_content['lat/attr/standard_name'] = 'latitude'
    file_content['lat/attr/units'] = 'degrees_north'
    file_content['lat/attr/valid_min'] = -90.
    file_content['lat/attr/valid_max'] = 90.
    file_content['lat/shape'] = DEFAULT_FILE_SHAPE
    file_content['lon'] = DEFAULT_LON_DATA
    file_content['lon/attr/comment'] = 'Longitude of retrievals'
    file_content['lon/attr/long_name'] = 'longitude'
    file_content['lon/attr/standard_name'] = 'longitude'
    file_content['lon/attr/units'] = 'degrees_east'
    file_content['lon/attr/valid_min'] = -180.
    file_content['lon/attr/valid_max'] = 180.
    file_content['lon/shape'] = DEFAULT_FILE_SHAPE
    for k in ['sea_surface_temperature',
              'satellite_zenith_angle',
              'sea_ice_fraction',
              'wind_speed']:
        file_content[k] = DEFAULT_FILE_DATA[None, ...]
        file_content[k + '/attr/scale_factor'] = 1.1
        file_content[k + '/attr/add_offset'] = 0.1
        file_content[k + '/attr/units'] = 'some_units'
        file_content[k + '/attr/comment'] = 'comment'
        file_content[k + '/attr/standard_name'] = 'standard_name'
        file_content[k + '/attr/long_name'] = 'long_name'
        file_content[k + '/attr/valid_min'] = 0
        file_content[k + '/attr/valid_max'] = 65534
        file_content[k + '/attr/_FillValue'] = 65534
        file_content[k + '/shape'] = (1, DEFAULT_FILE_SHAPE[0], DEFAULT_FILE_SHAPE[1])
    file_content['l2p_flags'] = np.zeros(
        (1, DEFAULT_FILE_SHAPE[0], DEFAULT_FILE_SHAPE[1]),
        dtype=np.uint16)
    convert_file_content_to_data_array(file_content, dims=("time", "nj", "ni"))
    return file_content