code: def save_ply(self, path):
      mkdir_p(os.path.dirname(path))
  
      xyz = self._xyz.detach().cpu().numpy()
      normals = np.zeros_like(xyz)
      f_dc = (
          self._features_dc.detach()
          .transpose(1, 2)
          .flatten(start_dim=1)
          .contiguous()
          .cpu()
          .numpy()
      )
      f_rest = (
          self._features_rest.detach()
          .transpose(1, 2)
          .flatten(start_dim=1)
          .contiguous()
          .cpu()
          .numpy()
      )
      opacities = self._opacity.detach().cpu().numpy()
      scale = self._scaling.detach().cpu().numpy()
      rotation = self._rotation.detach().cpu().numpy()
  
      dtype_full = [
          (attribute, "f4")
          for attribute in self.construct_list_of_attributes()
      ]
  
      elements = np.empty(xyz.shape[0], dtype=dtype_full)
      attributes = np.concatenate(
          (xyz, normals, f_dc, f_rest, opacities, scale, rotation),
          axis=1,
      )
      elements[:] = list(map(tuple, attributes))
      el = PlyElement.describe(elements, "vertex")
      PlyData([el]).write(path)
  
imports: import torch
  import numpy
  from utils.general_utils import inverse_sigmoid, get_expon_lr_func, build_rotation
  from torch import nn
  import os
  from utils.system_utils import mkdir_p
  from plyfile import PlyData, PlyElement
  from utils.sh_utils import RGB2SH
  from simple_knn._C import distCUDA2
  from utils.graphics_utils import BasicPointCloud
  from utils.general_utils import strip_symmetric, build_scaling_rotation
label_desc: Use image node_id 16 for calling the GaussianModel obj's underlying member method code with example usage: obj.save_ply(path) without return types