class_docstr: Display the progress bar itself.
class_docstr_tok: ["Display","the","progress","bar","itself","."]
code: def __init__(
      self,
      start: str = "[",
      end: str = "]",
      sym_a: str = "=",
      sym_b: str = ">",
      sym_c: str = " ",
      unknown: str = "#",
  ) -> None:
      assert len(sym_a) == 1 and get_cwidth(sym_a) == 1
      assert len(sym_c) == 1 and get_cwidth(sym_c) == 1
  
      self.start = start
      self.end = end
      self.sym_a = sym_a
      self.sym_b = sym_b
      self.sym_c = sym_c
      self.unknown = unknown
  
imports: from __future__ import annotations
  import datetime
  import time
  from abc import ABCMeta, abstractmethod
  from typing import TYPE_CHECKING
  from prompt_toolkit.formatted_text import HTML, AnyFormattedText, StyleAndTextTuples, to_formatted_text
  from prompt_toolkit.formatted_text.utils import fragment_list_width
  from prompt_toolkit.layout.dimension import AnyDimension, D
  from prompt_toolkit.layout.utils import explode_text_fragments
  from prompt_toolkit.utils import get_cwidth
label_desc: Use image node_id 1 to create a new Bar object from inherited base classes: Formatter with example: obj = Bar(start, end, sym_a, sym_b, sym_c, unknown)