code: def modis_l1b_imapp_1000m_file(tmpdir_factory) -> list[str]:
      """Create a single MOD021KM file following IMAPP file scheme."""
      filename = generate_imapp_filename("1000m")
      full_path = str(tmpdir_factory.mktemp("modis_l1b").join(filename))
      variable_infos = _get_l1b_geo_variable_info(
          filename, 5000, include_angles=True
      )
      variable_infos.update(
          _get_visible_variable_info(
              "EV_1KM_RefSB", 1000, AVAILABLE_1KM_VIS_PRODUCT_NAMES
          )
      )
      variable_infos.update(
          _get_visible_variable_info(
              "EV_500_Aggr1km_RefSB", 1000, AVAILABLE_HKM_PRODUCT_NAMES
          )
      )
      variable_infos.update(
          _get_visible_variable_info(
              "EV_250_Aggr1km_RefSB", 1000, AVAILABLE_QKM_PRODUCT_NAMES
          )
      )
      variable_infos.update(
          _get_emissive_variable_info(
              "EV_1KM_Emissive", 1000, AVAILABLE_1KM_IR_PRODUCT_NAMES
          )
      )
      create_hdfeos_test_file(
          full_path,
          variable_infos,
          _create_struct_metadata(5000),
          _create_core_metadata("MOD021KM"),
          _create_header_metadata(),
      )
      return [full_path]
  
imports: from __future__ import annotations
  from datetime import datetime, timedelta
  from typing import Optional
  import numpy
  import pytest
  from pyhdf.SD import SD, SDC
label_desc: Use image node_id 20 for calling a global function with example usage: modis_l1b_imapp_1000m_file(tmpdir_factory) and returns: list