code: def __setitem__(self, idx, val):
      if isinstance(idx, int):
          idx += self.size
          self.values[idx] = val
          self._percolate_up(idx, val)
      elif isinstance(idx, list):
          for i, idxx in enumerate(idx):
              idxx += self.size
              self.values[idxx] = val[i]
              self._percolate_up(idxx, val[i])
      else:
          raise RuntimeError("Not indexable type")
  
file_path: dynet/examples/reinforcement-learning/reduce_tree.py
imports: import operator
  import numpy
label_desc: Use image node_id 3 for calling the ReduceTree obj's underlying member method code with example usage: obj.__setitem__(idx, val) without return types