def METHOD_NAME(self):
    self.delete_renditions()
    # checking when command is called without any arguments
    output = self.run_command()
    output_string = self.REAESC.sub("", output.read())
    self.assertEqual(output_string, "No image renditions found.\n")
    # checking when command is called with '--purge-only'
    output = self.run_command(purge_only=True)
    output_string = self.REAESC.sub("", output.read())
    self.assertEqual(output_string, "No image renditions found.\n")