code: def convs(self, x, pos, edge_index):
      raise NotImplementedError
  
imports: from abc import abstractmethod
  from typing import *
  import torch
  from torch.nn import Linear, ReLU, LeakyReLU, BatchNorm1d, Dropout
  from torch_geometric.nn import knn_interpolate, fps, radius, global_max_pool, global_mean_pool, knn
  from torch_geometric.data import Batch
  from torch_points3d.core.base_conv.base_conv import *
  from torch_points3d.core.common_modules import *
  from torch_points3d.core.spatial_ops import *
label_desc: Use image node_id 2 for calling the BaseResnetBlockDown obj's underlying member method code with example usage: obj.convs(x, pos, edge_index) without return types