class_docstr: Manages placeholders associated with batch of graphs and their topology
docstr: Returns topology placeholders
  
  Consists of deg_slice_placeholder, membership_placeholder, and the
  deg_adj_list_placeholders.
docstr_tok: ["Returns","topology","placeholders","Consists","of","deg_slice_placeholder",",","membership_placeholder",",","and","the","deg_adj_list_placeholders","."]
code: def get_topology_placeholders(self):
      """Returns topology placeholders
  
      Consists of deg_slice_placeholder, membership_placeholder, and the
      deg_adj_list_placeholders.
      """
      return self.topology
  
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import unicode_literals
  import warnings
  import numpy
  import tensorflow
  from deepchem.nn.copy import Input
  from deepchem.feat.mol_graphs import ConvMol
label_desc: Use image node_id 3 for calling the GraphTopology obj's underlying member method code with example usage: obj.get_topology_placeholders() and returns: self