Zend_Soap_Wsdl constructor takes three parameters:
$name- name of the Web Service being described.
$uri- URI where the WSDL will be available (could also be a reference to the file in the filesystem.)
$strategy- optional flag used to identify the strategy for complex types (objects) detection. This was a boolean
$extractComplexTypesbefore version 1.7 and can still be set as a boolean for backwards compatibility. By default the 1.6 detection behaviour is set. To read more on complex type detection strategies go to the section: Add complex types.