code: def test_stack_outputfile(in_paths, out_path):
      """Test successful creation of output file."""
  
      # Test valid use case specifying output file.
      stack_arr, stack_prof = es.stack(in_paths, out_path)
  
      assert os.path.exists(out_path)
  
file_path: earthpy/earthpy/tests/test_stack.py
imports: import os
  import numpy
  import pytest
  import earthpy.spatial
label_desc: Use image node_id 12 for calling a global function with example usage: test_stack_outputfile(in_paths, out_path) without return types