class_docstr: Test all graphers with WAV input media format
class_docstr_tok: ["Test","all","graphers","with","WAV","input","media","format"]
code: def tearDown(self):
      decoder = FileDecoder(self.source)
      (decoder | self.grapher).run()
      self.grapher.render(self.image)
      self.assertGreater(os.path.getsize(self.image.name), 0)
      self.image.close()
  
file_path: TimeSide/tests/test_graphing.py
imports: from timeside.plugins.decoder.aubio import AubioDecoder
  import unittest
  from unit_timeside import TestRunner
  from timeside.core.tools.test_samples import samples
  import tempfile
  import os.path
label_desc: Use image node_id 9 for calling the TestGraphing obj's underlying member method code with example usage: obj.tearDown() without return types