code: def conv(self, x, pos, edge_index, batch):
      return self._conv(x, pos, edge_index)
  
imports: import torch
  import torch.nn.functional
  from torch_geometric.nn import MessagePassing
  from torch_points3d.core.spatial_ops import *
  from torch_points3d.core.base_conv.message_passing import *
label_desc: Use image node_id 2 for calling the RandlaConv obj's underlying member method code with example usage: obj.conv(x, pos, edge_index, batch) and returns: self