class_docstr: ProgressBar class keeps an update of the iteration and output the corresponding update progress bar.
  
  Args:
      steps (int): The number of steps.
      bar_format (str, optional): User defined format for the bar_format. By default the setting is
          {percentage} |{bar}|. The two argument must be {percentage} and {bar}.
      bar_character (str): The bar character to use. (Default value = █ which is 'block'.)
      partial_bar_characters (str): A list of character to use when a fraction of the bar character
          could be used. (Default value =
          ``[" ", "▏", "▎", "▍", "▌", "▋", "▊", "▉"]``
          that is from " " through 1/8th to 7/8th blocks)
  
  Attributes:
      total_steps (int): The total steps to do.
      bar_format (str): The format of the bar.
      bar_character (str): The bar character.
      bar_length (int): The size of the bar.
      actual_steps (int): Number of steps done so far.
code: def progress_bar_formatting(self) -> str:
      percentage = self.actual_steps / self.total_steps
      bar_length_complete = (
          int(math.floor(percentage * self.bar_length))
          * self.bar_character
      )
      bar_length_incomplete = (
          self.bar_length - len(bar_length_complete) - 1
      ) * " "
  
      partial_character = ""
      if percentage < 1.0:
          partial_percentage = percentage * self.bar_length - len(
              bar_length_complete
          )
          partial_index = int(
              math.floor(
                  partial_percentage * len(self.partial_bar_characters)
              )
          )
          partial_character = self.partial_bar_characters[partial_index]
  
      progress_bar = (
          bar_length_complete
          + partial_character
          + bar_length_incomplete
      )
      return progress_bar
  
imports: import math
  from typing import Optional
label_desc: Use image node_id 5 for calling the ProgressBar obj's underlying member method code with example usage: obj.progress_bar_formatting() and returns: progress_bar