class_docstr: Window node.
code: def _to_cols(self, rows: List[Dict]):
      ret = dict((key, []) for key in self._node_repr.inputs)
      for row in rows:
          for k, v in row.items():
              ret[k].append(v)
      return ret
  
file_path: towhee/towhee/runtime/nodes/_window_base.py
imports: from typing import List, Dict
  from towhee.runtime.data_queue import Empty
  from towhee.runtime.time_profiler import Event
  from .node import Node
  from ._single_input import SingleInputMixin
label_desc: Use image node_id 7 for calling the WindowBase obj's underlying member method code with example usage: obj._to_cols(rows) and returns: ret