code: def get_node(self, key):
          
          self._check_if_open()
          try:
              if not key.startswith('/'):
                  key = '/' + key
              return self._handle.get_node(self.root, key)
          except _table_mod.exceptions.NoSuchNodeError:
              return None
docs: return the node with the key or None if it does not exist