docstr: Add asset and op collections to be saved.
docstr_tok: ["Add","asset","and","op","collections","to","be","saved","."]
code: def _add_collections(self, assets_collection, main_op, train_op):
      """Add asset and op collections to be saved."""
      # Save asset files and write them to disk, if any.
      self._save_and_write_assets(assets_collection)
  
      self._maybe_add_main_op(main_op)
  
      self._add_train_op(train_op)
  
imports: import functools
  import os
  from google.protobuf.any_pb2 import Any
  from tensorflow.core.framework import types_pb2
  from tensorflow.core.protobuf import meta_graph_pb2
  from tensorflow.core.protobuf import saved_model_pb2
  from tensorflow.core.protobuf import saver_pb2
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor
  from tensorflow.python.lib.io import file_io
  from tensorflow.python.ops import variables
  from tensorflow.python.platform import tf_logging
  from tensorflow.python.saved_model import fingerprinting_utils
  from tensorflow.python.saved_model import path_helpers
  from tensorflow.python.saved_model import signature_def_utils
  from tensorflow.python.saved_model.pywrap_saved_model import constants
  from tensorflow.python.saved_model.pywrap_saved_model import metrics
  from tensorflow.python.training import saver
  from tensorflow.python.util import compat
  from tensorflow.python.util.deprecation import deprecated_args
  from tensorflow.python.util.tf_export import tf_export
label_desc: Use image node_id 2 for calling the SavedModelBuilder obj's underlying member method code with example usage: obj._add_collections(assets_collection, main_op, train_op) without return types