code: def __init__(self, x_size, h_size):
      super(ChildSumTreeLSTMCell, self).__init__()
      self.W_iou = nn.Linear(x_size, 3 * h_size, bias=False)
      self.U_iou = nn.Linear(h_size, 3 * h_size, bias=False)
      self.b_iou = nn.Parameter(th.zeros(1, 3 * h_size))
      self.U_f = nn.Linear(h_size, h_size)
  
imports: import itertools
  import time
  import dgl
  import networkx
  import numpy
  import torch
  import torch.nn
  import torch.nn.functional
label_desc: Use image node_id 1 to create a new ChildSumTreeLSTMCell object from inherited base classes: nn with example: obj = ChildSumTreeLSTMCell(x_size, h_size)