docstr: Attaches an optimizer to the graph.
docstr_tok: ["Attaches","an","optimizer","to","the","graph","."]
code: def get_training_op(self, loss):
      """Attaches an optimizer to the graph."""
      opt = tf.train.AdamOptimizer(self.learning_rate)
      return opt.minimize(self.loss_op, name="train")
  
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import unicode_literals
  import warnings
  import numpy
  import tensorflow
  import sys
  import time
  from deepchem.models import Model
  from deepchem.data import pad_batch
  from deepchem.data import NumpyDataset
  from deepchem.metrics import to_one_hot
  from deepchem.metrics import from_one_hot
  from deepchem.models.tf_new_models.graph_topology import merge_dicts
  from deepchem.nn import model_ops
  from deepchem.data import SupportGenerator
  from deepchem.data import EpisodeGenerator
  from deepchem.data import get_task_dataset
  from deepchem.data import get_single_task_test
  from deepchem.data import get_task_dataset_minus_support
  from deepchem.nn.copy import Input
label_desc: Use image node_id 2 for calling the SupportGraphClassifier obj's underlying member method code with example usage: obj.get_training_op(loss) and returns: opt