new_contents: from __future__ import division
  
  import numpy as np
  from skimage import io
  
  io.use_plugin('matplotlib', 'imshow')
  
  
  # test images. Note that they don't have their full range for their dtype,
  # but we still expect the display range to equal the full dtype range.
  im8 = np.array([[0, 64], [128, 240]], np.uint8)
  im16 = im8.astype(np.uint16) * 256
  imf = im8 / 255
  im_lo = imf / 1000
  im_hi = imf + 10
  
  
  
  def n_subplots(ax_im):
      """Return the number of subplots in the figure containing an ``AxesImage``.
  
      Parameters
      ----------
      ax_im : matplotlib.pyplot.AxesImage object
          The input ``AxesImage``.
  
      Returns
      -------
      n : int
          The number of subplots in the corresponding figure.
  
      Notes
      -----
      This function is intended to check whether a colorbar was drawn, in
      which case two subplots are expected. For standard imshows, one
      subplot is expected.
      """
      return len(ax_im.get_figure().get_axes())
  
  
  def test_uint8():
      ax_im = io.imshow(im8)
      assert ax_im.cmap.name == 'gray'
      assert ax_im.get_clim() == (0, 255)
      assert n_subplots(ax_im) == 1
  
  
  def test_uint16():
      ax_im = io.imshow(im16)
      assert ax_im.cmap.name == 'gray'
      assert ax_im.get_clim() == (0, 65535)
      assert n_subplots(ax_im) == 1
  
  
  def test_float():
      ax_im = io.imshow(imf)
      assert ax_im.cmap.name == 'gray'
      assert ax_im.get_clim() == (0, 1)
      assert n_subplots(ax_im) == 1
  
  
  if __name__ == '__main__':
      np.testing.run_module_suite()
  
subject: Add tests for io.imshow mpl plugin