class_docstr: A Batch wraps a pyarrow.RecordBatch and provides caching functionality.
  
  This is useful when several different generators need to apply the same
  computation to the same input record batch. A CompositeCombinerStatsGenerator
  instantiates an InputBatch and then passes it to the add_input method of each
  constituent generator. This allows the constituent generators to reuse
  expensive operations that have already been computed by other constituents.
docstr: Returns a boolean mask of rows which are null in the referenced array.
  
  If the requested path cannot be found in the record batch, it will be
  considered null in all rows in the record batch.
  
  Args:
    path: The path corresponding to the array from which to generate the null
      mask.
docstr_tok: ["Returns","a","boolean","mask","of","rows","which","are","null","in","the","referenced","array",".","If","the","requested","path","can","not","be","found","in","the","record","batch",",","it","will","be","considered","null","in","all","rows","in","the","record","batch",".","Args",":","path",":","The","path","corresponding","to","the","array","from","which","to","generate","the","null","mask","."]
code: def null_mask(self, path: types.FeaturePath) -> np.ndarray:
      """Returns a boolean mask of rows which are null in the referenced array.
  
      If the requested path cannot be found in the record batch, it will be
      considered null in all rows in the record batch.
  
      Args:
        path: The path corresponding to the array from which to generate the null
          mask.
      """
      try:
          array, _ = table_util.get_array(
              self._record_batch,
              tfx_bsl_path.ColumnPath(path.steps()),
              return_example_indices=False,
          )
          # GetArrayNullBitmapAsByteArray is only useful for non-null type arrays.
          if pa.types.is_null(array.type):
              return np.full(self._record_batch.num_rows, True)
          return np.asarray(
              array_util.GetArrayNullBitmapAsByteArray(array),
              dtype=bool,
          )
      except KeyError:
          return np.full(self._record_batch.num_rows, True)
  
file_path: data-validation/tensorflow_data_validation/statistics/generators/input_batch.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import numpy
  import pyarrow
  from tensorflow_data_validation import types
  from tfx_bsl.arrow import array_util
  from tfx_bsl.arrow import path
  from tfx_bsl.arrow import table_util
label_desc: Use image node_id 3 for calling the InputBatch obj's underlying member method code with example usage: obj.null_mask(path) and returns: np, np, np