code: def get_start_of_line_position(self, after_whitespace=False):
          
          if after_whitespace:
              current_line = self.current_line
              return len(current_line) - len(current_line.lstrip()) - self.cursor_position_col
          else:
              return - len(self.current_line_before_cursor)
docs: Relative position for the start of this line.