message: Fixing BigQuery connector
diff: @@ -29,8 +29,8 @@ from __future__ import print_function
  from tensorflow.python.data.experimental.ops import interleave_ops
  from tensorflow.python.data.ops import dataset_ops
  -from tensorflow.python.data.util import structure
  from tensorflow.python.framework import dtypes
  +from tensorflow.python.framework import tensor_spec
  from tensorflow_io.core.python.ops import _load_library
  @@ -223,8 +223,8 @@ class _BigQueryDataset(dataset_ops.DatasetSource):
  def __init__(self, client_resource, selected_fields, output_types,
  avro_schema, stream):
  - self._structure = structure.NestedStructure(
  - tuple(structure.TensorStructure(dtype, []) for dtype in output_types))
  + self._element_spec = tuple(
  + tensor_spec.TensorSpec([], dtype) for dtype in output_types)
  variant_tensor = _bigquery_so.big_query_dataset(
  client=client_resource,
  @@ -235,5 +235,5 @@ class _BigQueryDataset(dataset_ops.DatasetSource):
  super(_BigQueryDataset, self).__init__(variant_tensor)
  @property
  - def _element_structure(self):
  - return self._structure
  + def element_spec(self):
  + return self._element_spec
  