class_docstr: A minimal MovieWriter.  It doesn't actually write anything.
  It just saves the arguments that were given to the setup() and
  grab_frame() methods as attributes, and counts how many times
  grab_frame() is called.
  
  This class doesn't have an __init__ method with the appropriate
  signature, and it doesn't define an isAvailable() method, so
  it cannot be added to the 'writers' registry.
class_docstr_tok: ["A","minimal","MovieWriter",".","It","does","n't","actually","write","anything",".","It","just","saves","the","arguments","that","were","given","to","the","setup","(",")","and","grab_frame","(",")","methods","as","attributes",",","and","counts","how","many","times","grab_frame","(",")","is","called",".","This","class","does","n't","have","an","__init__","method","with","the","appropriate","signature",",","and","it","does","n't","define","an","isAvailable","(",")","method",",","so","it","can","not","be","added","to","the","'writers","'","registry","."]
code: def finish(self):
      pass
  
imports: import os
  from pathlib import Path
  import platform
  import re
  import shutil
  import subprocess
  import sys
  import weakref
  import numpy
  import pytest
  import matplotlib
  from matplotlib import pyplot
  from matplotlib import animation
  from matplotlib.testing.decorators import check_figures_equal
label_desc: Use image node_id 3 for calling the NullMovieWriter obj's underlying member method code with example usage: obj.finish() without return types