class_docstr: Parent class for deepchem Tensorflow models.
  
  Classifier:
    n_classes
  
  Has the following attributes:
  
    placeholder_root: String placeholder prefix, used to create
      placeholder_scope.
  
  Generic base class for defining, training, and evaluating TensorflowGraphs.
  
  Subclasses must implement the following methods:
    build
    add_output_ops
    add_training_cost 
  
  Args:
    train: If True, model is in training mode.
    logdir: Directory for output files.
class_docstr_tok: ["Parent","class","for","deepchem","Tensorflow","models",".","Classifier",":","n_classes","Has","the","following","attributes",":","placeholder_root",":","String","placeholder","prefix",",","used","to","create","placeholder_scope",".","Generic","base","class","for","defining",",","training",",","and","evaluating","TensorflowGraphs",".","Subclasses","must","implement","the","following","methods",":","build","add_output_ops","add_training_cost","Args",":","train",":","If","True",",","model","is","in","training","mode",".","logdir",":","Directory","for","output","files","."]
docstr: Restores the model from the provided training checkpoint.
  
  Args:
    checkpoint: string. Path to checkpoint file.
docstr_tok: ["Restores","the","model","from","the","provided","training","checkpoint",".","Args",":","checkpoint",":","string",".","Path","to","checkpoint","file","."]
code: def restore(self):
      """Restores the model from the provided training checkpoint.
  
      Args:
        checkpoint: string. Path to checkpoint file.
      """
      if self._restored_model:
          return
      with self.eval_graph.graph.as_default():
          last_checkpoint = self._find_last_checkpoint()
          # TODO(rbharath): Is setting train=False right here?
          saver = tf.train.Saver()
          saver.restore(
              self._get_shared_session(train=False), last_checkpoint
          )
          self._restored_model = True
  
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import unicode_literals
  import collections
  import pickle
  import os
  import time
  import warnings
  import numpy
  import pandas
  import tensorflow
  import tempfile
  from deepchem.models import Model
  from deepchem.metrics import from_one_hot
  from deepchem.nn import model_ops
  from deepchem.models.tensorflow_models import utils
  from deepchem.trans import undo_transforms
  from deepchem.utils.save import log
  from deepchem.utils.evaluate import Evaluator
  from deepchem.data import pad_features
  from tensorflow.contrib.layers.python.layers import batch_norm
label_desc: Use image node_id 16 for calling the TensorflowGraphModel obj's underlying member method code with example usage: obj.restore() without return types