class_docstr: Tests for LiftStatsGenerator.
class_docstr_tok: ["Tests","for","LiftStatsGenerator","."]
code: def test_lift_float_y_is_nan(self):
      # after calling bin_array, this is effectively an empty array.
      examples = [
          pa.RecordBatch.from_arrays(
              [
                  pa.array([["a"]]),
                  pa.array([[np.nan]]),
              ],
              ["categorical_x", "float_y"],
          ),
      ]
      schema = text_format.Parse(
          """
          feature {
            name: 'categorical_x'
            type: BYTES
          }
          feature {
            name: 'float_y'
            type: FLOAT
          }
          """,
          schema_pb2.Schema(),
      )
      expected_result = []
      generator = lift_stats_generator.LiftStatsGenerator(
          schema=schema,
          y_path=types.FeaturePath(["float_y"]),
          y_boundaries=[1],
      )
      self.assertSlicingAwareTransformOutputEqual(
          examples,
          generator,
          expected_result,
          add_default_slice_key_to_input=True,
          add_default_slice_key_to_output=True,
      )
  
imports: from typing import Optional, Sequence, Text
  from absl.testing import absltest
  import apache_beam
  import numpy
  import pandas
  import pyarrow
  from tensorflow_data_validation import types
  from tensorflow_data_validation.statistics.generators import lift_stats_generator
  from tensorflow_data_validation.utils import test_util
  from tensorflow_data_validation.utils.example_weight_map import ExampleWeightMap
  from google.protobuf import text_format
  from tensorflow_metadata.proto.v0 import schema_pb2
  from tensorflow_metadata.proto.v0 import statistics_pb2
label_desc: Use image node_id 18 for calling the LiftStatsGeneratorTest obj's underlying member method code with example usage: obj.test_lift_float_y_is_nan() without return types