code: def test_StrCategoryLocatorPlot(self, plotter):
      ax = plt.figure().subplots()
      plotter(ax, [1, 2, 3], ["a", "b", "c"])
      np.testing.assert_array_equal(ax.yaxis.major.locator(), range(3))
  
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 2 for calling the TestStrCategoryLocator obj's underlying member method code with example usage: obj.test_StrCategoryLocatorPlot(plotter) without return types