class_docstr: A sampling graph in CSC format.
class_docstr_tok: ["A","sampling","graph","in","CSC","format","."]
docstr: Returns the node type to id dictionary if present.
  
  Returns
  -------
  Dict[str, int] or None
      If present, returns a dictionary mapping node type to node type
      id.
docstr_tok: ["Returns","the","node","type","to","id","dictionary","if","present",".","Returns","--","--","--","-","Dict","[","str",",","int","]","or","None","If","present",",","returns","a","dictionary","mapping","node","type","to","node","type","id","."]
code: def node_type_to_id(self) -> Optional[Dict[str, int]]:
      """Returns the node type to id dictionary if present.
  
      Returns
      -------
      Dict[str, int] or None
          If present, returns a dictionary mapping node type to node type
          id.
      """
      return self._c_csc_graph.node_type_to_id()
  
imports: from typing import Dict, Optional, Union
  import torch
  from dgl.utils import recursive_apply
  from ...base import EID, ETYPE, NID, NTYPE
  from ...convert import to_homogeneous
  from ...heterograph import DGLGraph
  from ..base import etype_str_to_tuple, etype_tuple_to_str, ORIGINAL_EDGE_ID
  from ..sampling_graph import SamplingGraph
  from .sampled_subgraph_impl import CSCFormatBase, SampledSubgraphImpl
label_desc: Use image node_id 16 for calling the FusedCSCSamplingGraph obj's underlying member method code with example usage: obj.node_type_to_id() and returns: self