code: def __init__(self):
      self.__memo = weakref.WeakValueDictionary()
  
imports: import _symtable
  from _symtable import USE, DEF_GLOBAL, DEF_NONLOCAL, DEF_LOCAL, DEF_PARAM, DEF_IMPORT, DEF_BOUND, DEF_ANNOT, SCOPE_OFF, SCOPE_MASK, FREE, LOCAL, GLOBAL_IMPLICIT, GLOBAL_EXPLICIT, CELL
  import weakref
label_desc: Use image node_id 1 to create a new SymbolTableFactory object  with example: obj = SymbolTableFactory()