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
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.