content: from collections import namedtuple
  
  import pytorch_lightning as pl
  import torch
  import torch.nn as nn
  from pointnet2_ops.pointnet2_modules import PointnetFPModule, PointnetSAModuleMSG
  
  from pointnet2.models.pointnet2_ssg_sem import PointNet2SemSegSSG
  
  
  class PointNet2SemSegMSG(PointNet2SemSegSSG):
      def _build_model(self):
          self.SA_modules = nn.ModuleList()
          c_in = 6
          self.SA_modules.append(
              PointnetSAModuleMSG(
                  npoint=1024,
                  radii=[0.05, 0.1],
                  nsamples=[16, 32],
                  mlps=[[c_in, 16, 16, 32], [c_in, 32, 32, 64]],
                  use_xyz=self.hparams["model.use_xyz"],
              )
          )
          c_out_0 = 32 + 64
  
          c_in = c_out_0
          self.SA_modules.append(
              PointnetSAModuleMSG(
                  npoint=256,
                  radii=[0.1, 0.2],
                  nsamples=[16, 32],
                  mlps=[[c_in, 64, 64, 128], [c_in, 64, 96, 128]],
                  use_xyz=self.hparams["model.use_xyz"],
              )
          )
          c_out_1 = 128 + 128
  
          c_in = c_out_1
          self.SA_modules.append(
              PointnetSAModuleMSG(
                  npoint=64,
                  radii=[0.2, 0.4],
                  nsamples=[16, 32],
                  mlps=[[c_in, 128, 196, 256], [c_in, 128, 196, 256]],
                  use_xyz=self.hparams["model.use_xyz"],
              )
          )
          c_out_2 = 256 + 256
  
          c_in = c_out_2
          self.SA_modules.append(
              PointnetSAModuleMSG(
                  npoint=16,
                  radii=[0.4, 0.8],
                  nsamples=[16, 32],
                  mlps=[[c_in, 256, 256, 512], [c_in, 256, 384, 512]],
                  use_xyz=self.hparams["model.use_xyz"],
              )
          )
          c_out_3 = 512 + 512
  
          self.FP_modules = nn.ModuleList()
          self.FP_modules.append(PointnetFPModule(mlp=[256 + 6, 128, 128]))
          self.FP_modules.append(PointnetFPModule(mlp=[512 + c_out_0, 256, 256]))
          self.FP_modules.append(PointnetFPModule(mlp=[512 + c_out_1, 512, 512]))
          self.FP_modules.append(PointnetFPModule(mlp=[c_out_3 + c_out_2, 512, 512]))
  
          self.fc_lyaer = nn.Sequential(
              nn.Conv1d(128, 128, kernel_size=1, bias=False),
              nn.BatchNorm1d(128),
              nn.ReLU(True),
              nn.Dropout(0.5),
              nn.Conv1d(128, 13, kernel_size=1),
          )
  