class_docstr: Base Graph Model
class_docstr_tok: ["Base","Graph","Model"]
code: def loss(self):
      self.loss = L.softmax_with_cross_entropy(self.logits, self.labels)
      self.loss = L.reduce_mean(self.loss)
      self.metrics = {
          "loss": self.loss,
      }
  
imports: import os
  import re
  import time
  from random import random
  from functools import reduce, partial
  import numpy
  import multiprocessing
  import paddle
  import paddle.fluid
  import paddle.fluid
  import paddle.fluid.layers
  from pgl.graph_wrapper import GraphWrapper
  from pgl.layers.conv import gcn, gat
  from pgl.utils import paddle_helper
label_desc: Use image node_id 4 for calling the BaseGraph obj's underlying member method code with example usage: obj.loss() without return types