Description:
------------
---
From manual page: http://www.php.net/ds-pair.clear
---
It appears that there is an error in docs example.

Seems illogical that 
 
$pair = new \Ds\Pair("a", 1);
print_r($pair);

will output

Ds\Pair Object
(
    [0] => 1
    [1] => 2
    [2] => 3
)