code: def has_src(self):
      return os.path.isfile(self.src_file)
  
imports: from __future__ import print_function
  import argparse
  from datetime import datetime
  import logging
  import os
  import re
  import shutil
  import subprocess
  import sys
  import tarfile
label_desc: Use image node_id 12 for calling the AbstractBuilder obj's underlying member method code with example usage: obj.has_src() and returns: os