docstr: build model struct
docstr_tok: ["build","model","struct"]
code: def build_model(self):
      "build model struct"
      raise NotImplementError(self, self.build_model)
  
imports: import os
  import logging
  import paddle.fluid
label_desc: Use image node_id 2 for calling the ModelBase obj's underlying member method code with example usage: obj.build_model() without return types