code: def test_imshow_hovertemplate(binary_string):
      fig = px.imshow(img_rgb, binary_string=binary_string)
      assert (
          fig.data[0].hovertemplate
          == "x: %{x}<br>y: %{y}<br>color: [%{z[0]}, %{z[1]}, %{z[2]}]<extra></extra>"
      )
      fig = px.imshow(img_gray, binary_string=binary_string)
      if binary_string:
          assert (
              fig.data[0].hovertemplate
              == "x: %{x}<br>y: %{y}<extra></extra>"
          )
      else:
          assert (
              fig.data[0].hovertemplate
              == "x: %{x}<br>y: %{y}<br>color: %{z}<extra></extra>"
          )
  
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 24 for calling a global function with example usage: test_imshow_hovertemplate(binary_string) without return types