def preview_s(self) -> str:
    lines = self.s.splitlines()
    if (len(lines) > 8):
        lines = lines[:8]
        lines.append('... TRUNCATED')
    s = '\n'.join(lines)
    hor_line = (80 * '=')
    return f'''{hor_line}
{s}
{hor_line}'''
def preview_s(self) -> str:
    lines = self.s.splitlines()
    if (len(lines) > 8):
        lines = lines[:8]
        lines.append('... TRUNCATED')
    s = '\n'.join(lines)
    hor_line = (80 * '=')
    return f'{hor_line}
{s}
{hor_line}'