Description:
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If you set a token on get to use the cas-feature the return value of get is false

Reproduce code:
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$m = new Memcached();
$m->addServer('127.0.0.1', 11211, 1);

var_dump($m->set('key', 'value', 100));
var_dump($m->get('key', null));
var_dump($m->get('key', null, $token));
var_dump($token);

Expected result:
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bool(true)
string(5) "value"
string(5) "value"
float(4237)

Actual result:
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bool(true)
string(5) "value"
bool(false)
float(4237)