class_docstr: CSVIOTensor
docstr: Return a BaseIOTensor of bool for null values in `column`
code: def isnull(self, column):
      """Return a BaseIOTensor of bool for null values in `column`"""
      column_index = self.columns.index(
          next(e for e in self.columns if e == column)
      )
      spec = tf.nest.flatten(self.spec)[column_index]
      # change spec to bool
      spec = tf.TensorSpec(spec.shape, tf.bool)
      function = _IOTensorComponentLabelFunction(
          core_ops.io_csv_readable_read,
          self._resource,
          column,
          spec.shape,
          spec.dtype,
      )
  
      return io_tensor_ops.BaseIOTensor(spec, function, internal=True)
  
file_path: io/tensorflow_io/python/ops/csv_io_tensor_ops.py
imports: import uuid
  import tensorflow
  from tensorflow_io.python.ops import io_tensor_ops
  from tensorflow_io.python.ops import core_ops
label_desc: Use image node_id 2 for calling the CSVIOTensor obj's underlying member method code with example usage: obj.isnull(column) and returns: io_tensor_ops