code: def _addkey(self, key, pos_and_siz_pair):
      self._index[key] = pos_and_siz_pair
      with _io.open(self._dirfile, "a", encoding="Latin-1") as f:
          self._chmod(self._dirfile)
          f.write(
              "%r, %r\n" % (key.decode("Latin-1"), pos_and_siz_pair)
          )
  
imports: import ast
  import io
  import os
  import collections.abc
label_desc: Use image node_id 9 for calling the _Database obj's underlying member method code with example usage: obj._addkey(key, pos_and_siz_pair) without return types