code: def performGitDiff(self, fileName, verifyOutput):
      try:
          diffProcess = subprocess.Popen(
              [
                  "git",
                  "diff",
                  "--color=always",
                  "--exit-code",
                  "--no-index",
                  "--",
                  fileName,
                  "-",
              ],
              stdin=subprocess.PIPE,
              stdout=subprocess.PIPE,
              stderr=subprocess.PIPE,
          )
          diffOutput, _ = diffProcess.communicate(verifyOutput)
          if diffProcess.returncode == 0:
              diffOutput = ""
      except OSError:
          cprint("[ERROR] Failed to run git diff on " + fileName, "red")
          return (True, "")
      return (False, diffOutput)
  
imports: import argparse
  import filecmp
  import os
  import re
  import sets
  import subprocess
  import sys
  from termcolor import cprint
label_desc: Use image node_id 5 for calling the CodeFormatter obj's underlying member method code with example usage: obj.performGitDiff(fileName, verifyOutput) and returns: False,  diffOutput, True,  str