class_docstr: Another simple visual class. 
  
  Due to the simplicity of these example classes, it was only necessary to
  subclass from LineVisual and set the draw mode to 'points'. A more
  fully-featured PointVisual class might not follow this approach.
code: def __init__(self, pos=None, color=(1, 1, 1, 1)):
      LineVisual.__init__(self, pos, color)
      self._draw_mode = "points"
  
imports: import sys
  import numpy
  from vispy import app, gloo, visuals
  from vispy.visuals.filters import Clipper, ColorFilter
  from vispy.visuals.shaders import MultiProgram
  from vispy.visuals.collections import PointCollection
  from vispy.visuals.transforms import STTransform
  from vispy.scene import SceneCanvas
  from vispy.scene.visuals import create_visual_node
label_desc: Use image node_id 1 to create a new PointVisual object from inherited base classes: LineVisual with example: obj = PointVisual(pos, color)