class_docstr: Test that the parallax correction modifier works correctly.
docstr: Return datasets for BT and CTH for fake cloud.
docstr_tok: ["Return","datasets","for","BT","and","CTH","for","fake","cloud","."]
code: def _get_fake_cloud_datasets(self, test_area, cth, use_dask):
      """Return datasets for BT and CTH for fake cloud."""
      w_cloud = 20
      h_cloud = 5
  
      # location of cloud in uncorrected data
      lat_min_i = 155
      lat_max_i = lat_min_i + h_cloud
      lon_min_i = 140
      lon_max_i = lon_min_i + w_cloud
  
      fake_bt_data = (
          np.linspace(270, 330, math.prod(test_area.shape), dtype="f8")
          .reshape(test_area.shape)
          .round(2)
      )
      fake_cth_data = np.full(test_area.shape, np.nan, dtype="f8")
      fake_bt_data[lat_min_i:lat_max_i, lon_min_i:lon_max_i] = (
          np.linspace(180, 220, w_cloud * h_cloud)
          .reshape(h_cloud, w_cloud)
          .round(2)
      )
      fake_cth_data[lat_min_i:lat_max_i, lon_min_i:lon_max_i] = cth
  
      if use_dask:
          fake_bt_data = da.array(fake_bt_data)
          fake_cth_data = da.array(fake_cth_data)
  
      attrs = _get_attrs(0, 0)
  
      fake_bt = xr.DataArray(
          fake_bt_data,
          dims=("y", "x"),
          attrs={**attrs, "area": test_area},
      )
  
      fake_cth = xr.DataArray(
          fake_cth_data,
          dims=("y", "x"),
          attrs={**attrs, "area": test_area},
      )
  
      cma = np.zeros(shape=fake_bt.shape, dtype="?")
      cma[lat_min_i:lat_max_i, lon_min_i:lon_max_i] = True
  
      return (fake_bt, fake_cth, cma)
  
imports: import datetime
  import logging
  import math
  import os
  import unittest.mock
  import dask.array
  import dask.config
  import numpy
  import pyorbital.tlefile
  import pyresample.kd_tree
  import pytest
  import xarray
  from pyproj import Geod
  from pyresample import create_area_def
  import satpy.resample
  from satpy.tests.utils import xfail_skyfield_unstable_numpy2
  from satpy.writers import get_enhanced_image
label_desc: Use image node_id 4 for calling the TestParallaxCorrectionModifier obj's underlying member method code with example usage: obj._get_fake_cloud_datasets(test_area, cth, use_dask) and returns: fake_bt,  fake_cth,  cma