code: def test_iterate(fx_asset):
      """Uses iterator."""
      with Color("#000") as black:
          with Color("transparent") as transparent:
              with Image(
                  filename=str(fx_asset.joinpath("croptest.png"))
              ) as img:
                  for i, row in enumerate(img):
                      assert len(row) == 300
                      if i % 30:
                          continue  # avoid slowness
                      if 100 <= i < 200:
                          for x, color in enumerate(row):
                              if x % 30:
                                  continue  # avoid slowness
                              if 100 <= x < 200:
                                  assert color == black
                              else:
                                  assert color == transparent
                      else:
                          for color in row:
                              assert color == transparent
                  assert i == 299
  
imports: import codecs
  import io
  import os
  import os.path
  import shutil
  import struct
  import sys
  import tempfile
  from pytest import mark, raises
  from wand.image import ClosedImageError, Image
  from wand.color import Color
  from wand.font import Font
label_desc: Use image node_id 33 for calling a global function with example usage: test_iterate(fx_asset) without return types