code: def __enter__(self):
      if self._saved_value is not self._sentinel:
          raise RuntimeError("Already preserving saved value")
      self._saved_value = sys.argv[0]
      sys.argv[0] = self.value
  
imports: import sys
  import importlib.machinery
  import importlib.util
  import io
  import os
label_desc: Use image node_id 2 for calling the _ModifiedArgv0 obj's underlying member method code with example usage: obj.__enter__() without return types