Description:
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Reflection for openssl_open returns 5 required parameters "data", "opendata", "ekey", "privkey", "iv". But actually 5 parameter is optional. And parameters names also are different from documentation: http://php.net/openssl_open

Test script:
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$reflection = new ReflectionFunction('openssl_open');
$parameters = $reflection->getParameters();
var_dump($parameters[4]->isOptional()); // false


Expected result:
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`$parameters[4]->isOptional()` returns true

Actual result:
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`$parameters[4]->isOptional()` returns false