code: def _upgrade(self, old_file_text):
      in_file = io.StringIO(old_file_text)
      out_file = io.StringIO()
      upgrader = ast_edits.ASTCodeUpgrader(
          tf_upgrade_v2_safety.TFAPIChangeSpec()
      )
      count, report, errors = upgrader.process_opened_file(
          "test.py", in_file, "test_out.py", out_file
      )
      return count, report, errors, out_file.getvalue()
  
file_path: tensorflow-upstream/tensorflow/tools/compatibility/tf_upgrade_v2_safety_test.py
imports: import io
  from tensorflow.python.framework import test_util
  from tensorflow.python.platform import test
  from tensorflow.tools.compatibility import ast_edits
  from tensorflow.tools.compatibility import tf_upgrade_v2_safety
label_desc: Use image node_id 1 for calling the TfUpgradeV2SafetyTest obj's underlying member method code with example usage: obj._upgrade(old_file_text) and returns: count,  report,  errors,  out_file