code: def test_hist():
      fig, ax = plt.subplots()
      n, bins, patches = ax.hist(["a", "b", "a", "c", "ff"])
      assert n.shape == (10,)
      np.testing.assert_allclose(
          n, [2.0, 0.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0, 0.0, 1.0]
      )
  
imports: import warnings
  import pytest
  import numpy
  import matplotlib
  from matplotlib.axes import Axes
  import matplotlib.pyplot
  import matplotlib.category
  from matplotlib.testing.decorators import check_figures_equal
label_desc: Use image node_id 4 for calling a global function with example usage: test_hist() without return types