class_docstr: An intermediate representation for DL graph.
code: def add_node(self, node):
      assert node.name not in self.node_dict
      self.node_dict[node.name] = node
  
imports: import six
  from six import string_types
  from mmdnn.conversion.caffe.errors import ConversionError
  from mmdnn.conversion.common.IR.graph_pb2 import GraphDef, NodeDef, TensorShape
  from mmdnn.conversion.caffe.utils import get_real_name
label_desc: Use image node_id 4 for calling the Graph obj's underlying member method code with example usage: obj.add_node(node) without return types