code: def eval(self):
      if F.in_dygraph_mode():
          super(ErnieModel, self).eval()
      self.training = False
      for l in self.sublayers():
          l.training = False
  
imports: from __future__ import division
  from __future__ import absolute_import
  from __future__ import print_function
  from __future__ import unicode_literals
  import logging
  import paddle.fluid.dygraph
  import paddle.fluid
  import paddle.fluid.layers
label_desc: Use image node_id 2 for calling the ErnieModel obj's underlying member method code with example usage: obj.eval() without return types