code: def test_compact(self):
      input_ = "[ 1 ,\n 2]"
      expect = "[1,2]\n"
      args = sys.executable, "-m", "json.tool", "--compact"
      process = subprocess.run(
          args, input=input_, capture_output=True, text=True, check=True
      )
      self.assertEqual(process.stdout, expect)
      self.assertEqual(process.stderr, "")
  
imports: import errno
  import os
  import sys
  import textwrap
  import unittest
  import subprocess
  from test import support
  from test.support import os_helper
  from test.support.script_helper import assert_python_ok
label_desc: Use image node_id 13 for calling the TestTool obj's underlying member method code with example usage: obj.test_compact() without return types