PHP Server SDK example needed

PHP Server SDK example needed

I have installed the PHP Server SDK for API v2. I am trying to search for a record based on an email field. However, the searchRecords function only has searchWord, page, and perPage as arguments. I don't see how I can pass a search criteria such as email= bill@microsoft.com to this function. Unfortunatly, I have not been able to locate documentation for the functions. Is this SDK ready for use, and is documentation available? Can you provide an example on how to properly use the searchRecords function with a criteria to search a specific field? Thanks.