class_docstr: Creates a textarea for user to enter string input or display string output.
  Preprocessing: passes textarea value as a {str} into the function.
  Postprocessing: expects a {str} returned from function and sets textarea value to it.
  Examples-format: a {str} representing the textbox input.
  
  Demos: hello_world, diff_texts, sentence_builder
  Guides: creating-a-chatbot, real-time-speech-recognition
class_docstr_tok: ["Creates","a","textarea","for","user","to","enter","string","input","or","display","string","output",".","Preprocessing",":","passes","textarea","value","as","a","{","str","}","into","the","function",".","Postprocessing",":","expects","a","{","str","}","returned","from","function","and","sets","textarea","value","to","it",".","Examples-format",":","a","{","str","}","representing","the","textbox","input",".","Demos",":","hello_world",",","diff_texts",",","sentence_builder","Guides",":","creating-a-chatbot",",","real-time-speech-recognition"]
code: def postprocess(self, value: str | None) -> str | None:
      return None if value is None else str(value)
  
file_path: gradio/gradio/components/textbox.py
imports: from __future__ import annotations
  from typing import Any, Callable, Literal
  from gradio_client.documentation import document, set_documentation_group
  from gradio.components.base import FormComponent
  from gradio.events import Events
label_desc: Use image node_id 3 for calling the Textbox obj's underlying member method code with example usage: obj.postprocess(value) and returns: unknown