code: def test_ax_not_provided(rgb_image):
      """Test plot_rgb produces an output image when an axis object is
      not provided."""
  
      rgb_image, _ = rgb_image
      ax = plot_rgb(rgb_image)
      rgb_im_shape = rgb_image.transpose([1, 2, 0]).shape
      the_plot_im_shape = ax.get_images()[0].get_array().shape
      assert rgb_im_shape == the_plot_im_shape
      plt.close()
  
imports: import numpy
  import numpy.ma
  import matplotlib.pyplot
  import pytest
  import rasterio
  from rasterio.plot import plotting_extent
  from earthpy.plot import plot_rgb, _stretch_im
  from earthpy.io import path_to_example
label_desc: Use image node_id 8 for calling a global function with example usage: test_ax_not_provided(rgb_image) without return types