code: def _create_parameters():
      params = testing.product(
          {
              "file_obj": [False, True],
              "size": [(48, 32)],
              "dtype": [np.float32, np.uint8, bool],
          }
      )
      no_color_params = testing.product(
          {
              "format": ["bmp", "jpeg", "png"],
              "color": [False],
              "alpha": [None],
          }
      )
      no_alpha_params = testing.product(
          {
              "format": ["bmp", "jpeg", "png"],
              "color": [True],
              "alpha": [None],
          }
      )
      alpha_params = testing.product(
          {
              # writing alpha image with jpeg encoding didn't work
              "format": ["png"],
              "color": [True],
              "alpha": [
                  "ignore",
                  "blend_with_white",
                  "blend_with_black",
              ],
          }
      )
      params = testing.product_dict(
          params, no_color_params + no_alpha_params + alpha_params
      )
      return params
  
imports: import numpy
  import tempfile
  import unittest
  from PIL import Image
  import chainer
  from chainer import testing
  from chainercv.utils import read_image
  from chainercv.utils import write_image
label_desc: Use image node_id 2 for calling a global function with example usage: _create_parameters() and returns: params