code: def fake_iasi_l2_cdr_nc_file(fake_iasi_l2_cdr_nc_dataset, tmp_path):
      """Write a NetCDF file with minimal fake IASI L2 CDR NC data."""
      fn = (
          "W_XX-EUMETSAT-Darmstadt,HYPERSPECT+SOUNDING,METOPA+PW3+"
          "IASI_C_EUMP_19210624090000Z_19210623090100Z_eps_r_l2_0101.nc"
      )
      of = tmp_path / fn
      fake_iasi_l2_cdr_nc_dataset.to_netcdf(of)
      return os.fspath(of)
  
imports: import math
  import os
  import unittest
  import numpy
  import pytest
  import xarray
label_desc: Use image node_id 3 for calling a global function with example usage: fake_iasi_l2_cdr_nc_file(fake_iasi_l2_cdr_nc_dataset, tmp_path) and returns: os