code: def test_custom_functions():
      test_console = TestOutput()
  
      print_stats(
          test_stats, functions=[np.average], output=test_console
      )
  
      assert not any(
          s in test_console.display_output
          for s in ["Mean", "Median", "Amin", "Amax"]
      )
  
      assert "Average" in test_console.display_output
      assert "feature_name" in test_console.display_output
  
file_path: neon/tests/test_print_stats.py
imports: import numpy
  import pytest
  from neon.benchmark import Benchmark
label_desc: Use image node_id 2 for calling a global function with example usage: test_custom_functions() without return types