code: def test_histogram():
      """Test histogram visual"""
      size = (200, 100)
      with TestingCanvas(size=size, bgcolor="w") as c:
          np.random.seed(2397)
          data = np.random.normal(size=100)
          hist = Histogram(data, bins=20, color="k", parent=c.scene)
          hist.transform = STTransform(
              (size[0] // 10, -size[1] // 20, 1), (100, size[1])
          )
          assert_image_approved(c.render(), "visuals/histogram.png")
  
imports: import numpy
  from vispy.visuals.transforms import STTransform
  from vispy.scene.visuals import Histogram
  from vispy.testing import requires_application, TestingCanvas, run_tests_if_main
  from vispy.testing.image_tester import assert_image_approved
label_desc: Use image node_id 1 for calling a global function with example usage: test_histogram() without return types