code: def test_zmax():
      for zmax in [
          100,
          [100],
          (100,),
          [100, 100, 100],
          (100, 100, 100),
          (100, 100, 100, 255),
      ]:
          fig = px.imshow(img_rgb, zmax=zmax, binary_string=False)
          assert fig.data[0]["zmax"] == (100, 100, 100, 255)
  
imports: import plotly.express
  import numpy
  import pytest
  import xarray
  from PIL import Image
  from io import BytesIO
  import base64
  import datetime
  from plotly.express.imshow_utils import rescale_intensity
label_desc: Use image node_id 3 for calling a global function with example usage: test_zmax() without return types