code: def build(self):
      for layer in self.model.node:
          self.layer_map[layer.name] = IRGraphNode(layer)
          self.layer_name_map[layer.name] = layer.name
  
      for i, layer in enumerate(self.model.node):
          for pred in layer.input:
              self._make_connection(pred, layer.name)
  
      self.filter_node()
      super(IRGraph, self).build()
      self.input_layers = list(
          filter(
              lambda x: self.layer_map[x].type != "Constant",
              self.input_layers,
          )
      )
  
imports: import mmdnn.conversion.common.IR.graph_pb2
  from mmdnn.conversion.common.utils import *
  from mmdnn.conversion.common.IR.graph_pb2 import TensorShape, AttrValue
  from mmdnn.conversion.common.DataStructure.graph import Graph, GraphNode
label_desc: Use image node_id 4 for calling the IRGraph obj's underlying member method code with example usage: obj.build() without return types