code: def initialize_model(self, root_node):
          
  
          LOGGER.debug("> Initializing model with '{0}' root node.".format(root_node))
  
          self.beginResetModel()
          self.root_node = root_node
          self.enable_model_triggers(True)
          self.endResetModel()
          return True
docs: Initializes the Model using given root node.
  
          :param root_node: Graph root node.
          :type root_node: DefaultNode
          :return: Method success
          :rtype: bool