In this recent post to his blog Mike Purcell shares a method he found to discover the parameters required by a method in a class' parent via reflection.

According to PHP docs regarding the Memcached::get() method, there are three arguments which which must be added to my extended signature, which I added, but kept getting "...should be compatible with that of Memcached::get()" errors. I tried looking for the method signature via source code but didn't glean anything useful from the PECL documentation, so I turned to PHP's RelectionClass.

He includes a quick snippet of code showing how the check works and the handy output it produces - a set containing the parameter name, if it's require or optional and it's definition.