class_docstr: SaveableObject implementation for QuantileAccumulator.
  
  The bucket boundaries are serialized and deserialized from checkpointing.
code: def get_bucket_boundaries(self):
      return get_bucket_boundaries(
          self.resource_handle, self._num_streams
      )
  
imports: from tensorflow.python.framework import ops
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import gen_boosted_trees_ops
  from tensorflow.python.ops import resources
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_aggregate_stats
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_bucketize
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_calculate_best_feature_split
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_calculate_best_feature_split_v2
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_calculate_best_gains_per_feature
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_center_bias
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_create_quantile_stream_resource
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_example_debug_outputs
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_make_quantile_summaries
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_make_stats_summary
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_predict
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_quantile_stream_resource_add_summaries
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_quantile_stream_resource_deserialize
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_quantile_stream_resource_flush
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_quantile_stream_resource_get_bucket_boundaries
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_quantile_stream_resource_handle_op
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_sparse_aggregate_stats
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_sparse_calculate_best_feature_split
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_training_predict
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_update_ensemble
  from tensorflow.python.ops.gen_boosted_trees_ops import boosted_trees_update_ensemble_v2
  from tensorflow.python.ops.gen_boosted_trees_ops import is_boosted_trees_quantile_stream_resource_initialized
  from tensorflow.python.training import saver
label_desc: Use image node_id 10 for calling the QuantileAccumulator obj's underlying member method code with example usage: obj.get_bucket_boundaries() and returns: get_bucket_boundaries