docs: def _populate_lines(self, block, terminal, styles, default_esc_seq):
          '''Takes some lines to draw to the terminal, which may contain
          formatting placeholder objects, and inserts the appropriate concrete
          escapes sequences by using data from the terminal object and styles
          dictionary.
          '''
          for line in block:
              if hasattr(line, 'populate'):
                  line = line.populate(terminal, styles, default_esc_seq)
              else:
                  line = default_esc_seq + line
              yield line