class_docstr: Row of a tabular Dataset backed by a Pandas DataFrame block.
code: def __iter__(self) -> Iterator:
      for k in self._row.columns:
          yield k
  
imports: import collections
  import heapq
  from typing import TYPE_CHECKING, Any, Callable, Dict, Iterator, List, Optional, Tuple, TypeVar, Union
  import numpy
  from ray.air.constants import TENSOR_COLUMN_NAME
  from ray.data._internal.table_block import TableBlockAccessor, TableBlockBuilder
  from ray.data._internal.util import find_partitions
  from ray.data.block import Block, BlockAccessor, BlockExecStats, BlockMetadata, KeyType, U
  from ray.data.context import DataContext
  from ray.data.row import TableRow
label_desc: Use image node_id 2 for calling the PandasRow obj's underlying member method code with example usage: obj.__iter__() without return types