class_docstr: Import hook for a shim.
  
  This ensures that submodule imports return the real target module,
  not a clone that will confuse `is` and `isinstance` checks.
code: def find_spec(self, fullname, path, target=None):
      if fullname.startswith(self.src + "."):
          mirror_name = self._mirror_name(fullname)
          return importlib.util.find_spec(mirror_name)
  
imports: import importlib.abc
  import importlib.util
  import sys
  import types
  from importlib import import_module
  from .importstring import import_item
label_desc: Use image node_id 3 for calling the ShimImporter obj's underlying member method code with example usage: obj.find_spec(fullname, path, target) and returns: importlib