code: def input_spec(self):
      return _MODEL_INPUT_SPEC
  
imports: from absl.testing import absltest
  from lit_nlp.api import dataset
  from lit_nlp.api import model
  from lit_nlp.api import types
  from lit_nlp.components import pdp
  from lit_nlp.lib import testing_utils
label_desc: Use image node_id 1 for calling the TestClassificationPdp obj's underlying member method code with example usage: obj.input_spec() and returns: _MODEL_INPUT_SPEC