code: def test_sphere_decreasing():
      # Arrange
      middle = 0.5
      pos = 0.75
  
      # Act
      ret = GimpGradientFile.sphere_decreasing(middle, pos)
  
      # Assert
      assert ret == 0.3385621722338523
  
file_path: pillow-simd/Tests/test_file_gimpgradient.py
imports: from PIL import GimpGradientFile, ImagePalette
label_desc: Use image node_id 8 for calling a global function with example usage: test_sphere_decreasing() without return types