code: def test_hist_masked_array(image_array_2bands):
      """Test that a masked 2 band array plots properly"""
      masked_arr = np.ma.masked_where(
          image_array_2bands == 6, image_array_2bands
      )
      nbins = 6
      f, ax = ep.hist(masked_arr, bins=nbins)
      for a in ax:
          assert len(a.patches) == 6
      assert len(f.axes) == 2
      plt.close(f)
  
imports: import numpy
  import pytest
  import matplotlib.pyplot
  import earthpy.plot
label_desc: Use image node_id 18 for calling a global function with example usage: test_hist_masked_array(image_array_2bands) without return types