class_docstr: Represent a single graph with additional attributes.
class_docstr_tok: ["Represent","a","single","graph","with","additional","attributes","."]
docstr: Add a number of nodes to the graph.
  
  Parameters
  ------
  node_num: int
      The number of nodes to be added
code: def add_nodes(self, node_num: int):
      """
      Add a number of nodes to the graph.
  
      Parameters
      ------
      node_num: int
          The number of nodes to be added
      """
      assert (
          node_num > 0
      ), "The number of nodes to be added should be greater than 0. (Got {})".format(
          node_num
      )
  
      # Create placeholders in the node attribute dictionary
      self._node_attributes.extend(
          [
              single_node_attr_factory(**res_init_node_attr)
              for _ in range(node_num)
          ]
      )
  
      # Do padding in the node feature dictionary
      for key in self._node_features.keys():
          self._node_features[key] = entail_zero_padding(
              self._node_features[key], node_num
          )
  
imports: import os
  import warnings
  from collections import namedtuple
  from typing import Any, Callable, Dict, List, Tuple, Union
  import dgl
  import scipy.sparse
  import torch
  from torch.nn.utils.rnn import pad_sequence
  from .utils import EdgeNotFoundException, SizeMismatchException, check_and_expand, entail_zero_padding, int_to_list, slice_to_list
  from .views import BatchEdgeFeatView, BatchNodeFeatView, EdgeView, NodeFeatView, NodeView
label_desc: Use image node_id 5 for calling the GraphData obj's underlying member method code with example usage: obj.add_nodes(node_num) without return types