def ln(label):
label_len = len(label) + <NUM_LIT:2><EOL>chunk = (<NUM_LIT> - label_len) // <NUM_LIT:2><EOL>out = '<STR_LIT>' % ('<STR_LIT:->' * chunk, label, '<STR_LIT:->' * chunk)<EOL>pad = <NUM_LIT> - len(out)<EOL>if pad > <NUM_LIT:0>:<EOL><INDENT>out = out + ('<STR_LIT:->' * pad)<EOL><DEDENT>return out<EOL>
Draw a 70-char-wide divider, with label in the middle.

    >>> ln('hello there')
    '---------------------------- hello there -----------------------------'