code: def test_markers():
      """Test basic marker / point-sprite support"""
      # this is probably too basic, but it at least ensures that point sprites
      # work for people
      np.random.seed(57983)
      data = np.random.normal(size=(30, 2), loc=50, scale=10)
  
      with TestingCanvas() as c:
          marker = Markers(parent=c.scene)
          marker.set_data(data)
          assert_image_approved(c.render(), "visuals/markers.png")
  
      # Test good correlation at high-dpi
      with TestingCanvas(px_scale=2) as c:
          marker = Markers(parent=c.scene)
          marker.set_data(data)
          assert_image_approved(c.render(), "visuals/markers.png")
  
file_path: vispy/vispy/visuals/tests/test_markers.py
imports: import numpy
  import pytest
  from vispy.scene.visuals import Markers
  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_markers() without return types