Description:
------------
The first parameter of SoapClient::__setSoapHeaders is optional but it is described as required by reflection.

Test script:
---------------
php --rf SoapClient::__setSoapHeaders

Expected result:
----------------
Method [ <internal:soap> public method __setSoapHeaders ] {

  - Parameters [1] {
    Parameter #0 [ <optional> $soapheaders ]
  }
}

Actual result:
--------------
Method [ <internal:soap> public method __setSoapHeaders ] {

  - Parameters [1] {
    Parameter #0 [ <required> $soapheaders ]
  }
}