code: def test_neg_numbers():
      A = np.arange(-10, 10)
      scaled = stretch(A, 255)
      assert scaled.shape == A.shape
      assert scaled.min() <= 1
      assert scaled.max() >= 254
  
file_path: mahotas/mahotas/tests/test_stretch.py
imports: from mahotas.stretch import stretch
  import mahotas
  import mahotas
  import pytest
  import numpy
label_desc: Use image node_id 2 for calling a global function with example usage: test_neg_numbers() without return types