code: def _custom_fromfile(*args, **kwargs):
      from satpy.readers.ahi_hsd import (
          _BASIC_INFO_TYPE,
          _CAL_INFO_TYPE,
          _DATA_INFO_TYPE,
          _ERROR_INFO_TYPE,
          _ERROR_LINE_INFO_TYPE,
          _INTER_CALIBRATION_INFO_TYPE,
          _IRCAL_INFO_TYPE,
          _NAV_INFO_TYPE,
          _NAVIGATION_CORRECTION_INFO_TYPE,
          _NAVIGATION_CORRECTION_SUBINFO_TYPE,
          _OBSERVATION_LINE_TIME_INFO_TYPE,
          _OBSERVATION_TIME_INFO_TYPE,
          _PROJ_INFO_TYPE,
          _SEGMENT_INFO_TYPE,
          _SPARE_TYPE,
          _VISCAL_INFO_TYPE,
      )
  
      dtype = kwargs.get("dtype")
      fake_info_map = {
          _BASIC_INFO_TYPE: FAKE_BASIC_INFO,
          _DATA_INFO_TYPE: FAKE_DATA_INFO,
          _NAV_INFO_TYPE: FAKE_NAV_INFO,
          _PROJ_INFO_TYPE: FAKE_PROJ_INFO,
          _CAL_INFO_TYPE: FAKE_CAL_INFO,
          _VISCAL_INFO_TYPE: FAKE_IRVISCAL_INFO,
          _IRCAL_INFO_TYPE: FAKE_IRVISCAL_INFO,
          _INTER_CALIBRATION_INFO_TYPE: FAKE_INTERCAL_INFO,
          _SEGMENT_INFO_TYPE: FAKE_SEGMENT_INFO,
          _NAVIGATION_CORRECTION_INFO_TYPE: FAKE_NAVCORR_INFO,
          _NAVIGATION_CORRECTION_SUBINFO_TYPE: FAKE_NAVCORR_SUBINFO,
          _OBSERVATION_TIME_INFO_TYPE: FAKE_OBS_TIME_INFO,
          _OBSERVATION_LINE_TIME_INFO_TYPE: FAKE_OBS_LINETIME_INFO,
          _ERROR_INFO_TYPE: FAKE_ERROR_INFO,
          _ERROR_LINE_INFO_TYPE: FAKE_ERROR_LINE_INFO,
          _SPARE_TYPE: FAKE_SPARE_INFO,
      }
      info_dict = fake_info_map[dtype]
      fake_arr = np.zeros((1,), dtype=dtype)
      for key, value in info_dict.items():
          fake_arr[key] = value
      return fake_arr
  
imports: from __future__ import annotations
  import contextlib
  import unittest
  import warnings
  from datetime import datetime
  from typing import Any, Dict
  from unittest import mock
  import dask.array
  import numpy
  import pytest
  from satpy.readers.ahi_hsd import AHIHSDFileHandler
  from satpy.readers.utils import get_geostationary_mask
  from satpy.tests.utils import make_dataid
label_desc: Use image node_id 4 for calling a global function with example usage: _custom_fromfile() and returns: fake_arr