code: def _find_min_start(text, max_width, unicode_aware=True, at_end=False):
      
      # Is the solution trivial?  Worth optimizing for text heavy UIs...
      if 2 * len(text) < max_width:
          return 0
  
      # OK - do it the hard way...
      result = 0
      string_len = wcswidth if unicode_aware else len
      char_len = wcwidth if unicode_aware else lambda x: 1
      display_end = string_len(text)
      while display_end > max_width:
          result += 1
          display_end -= char_len(text[0])
          text = text[1:]
      if at_end and display_end == max_width:
          result += 1
      return result
docs: Find the starting point in the string that will reduce it to be less than or equal to the
      specified width when displayed on screen.
  
      :param text: The text to analyze.
      :param max_width: The required maximum width
      :param at_end: At the end of the editable line, so allow spaced for cursor.
  
      :return: The offset within `text` to start at to reduce it to the required length.