code: def fake_iasi_l2_cdr_nc_dataset():
      """Create minimally fake IASI L2 CDR NC dataset."""
      shp = (3, 4, 5)
      fv = -999
      dims = ("scan_lines", "pixels", "vertical_levels")
      coords2 = "latitude longitude"
      coords3 = "latitude longitude pressure_levels"
      lons = xr.DataArray(
          np.array(
              [[0, 0, 0, 0], [1, 1, 1, 1], [2, 2, 2, 2]],
              dtype="float32",
          ),
          dims=dims[:2],
          attrs={"coordinates": coords2, "standard_name": "longitude"},
      )
      lats = xr.DataArray(
          np.array(
              [[3, 3, 3, 3], [2, 2, 2, 2], [1, 1, 1, 1]],
              dtype="float32",
          ),
          dims=dims[:2],
          attrs={"coordinates": coords2, "standard_name": "latitude"},
      )
      pres = xr.DataArray(
          np.linspace(0, 1050, math.prod(shp), dtype="float32").reshape(
              shp
          ),
          dims=dims,
          attrs={"coordinates": coords3},
      )
  
      temps = np.linspace(
          100, 400, math.prod(shp), dtype="float32"
      ).reshape(shp)
      temps[0, 0, 0] = fv
      temp = xr.DataArray(
          temps,
          dims=dims,
          attrs={
              "coordinates": coords3,
              "_FillValue": fv,
              "units": "K",
          },
      )
  
      iasibad = xr.DataArray(
          np.zeros(shp[:2], dtype="uint8"),
          dims=dims[:2],
          attrs={
              "coordinates": coords2,
              "standard_name": "flag_information_IASI_L1c",
          },
      )
      iasibad[0, 0] = 1
  
      cf = xr.DataArray(
          np.zeros(shp[:2], dtype="uint8"),
          dims=dims[:2],
          attrs={
              "coordinates": coords2,
              "standard_name": "cloud_area_fraction",
              "_FillValue": 255,
              "valid_min": 0,
              "valid_max": 100,
          },
      )
  
      return xr.Dataset(
          {"T": temp, "FLG_IASIBAD": iasibad, "CloudFraction": cf},
          coords={
              "longitude": lons,
              "latitude": lats,
              "pressure_levels": pres,
          },
      )
  
imports: import math
  import os
  import unittest
  import numpy
  import pytest
  import xarray
label_desc: Use image node_id 2 for calling a global function with example usage: fake_iasi_l2_cdr_nc_dataset() and returns: xr