title: CheckAndPut operation with multiple columns
body: <p>I'm working on a prototype to evaluate the use of HBase in a real project (or not, depending on the results of the prototype). In the schema I'm working on I have multiple columns in the same column family and I need to update several of them atomically (always within the same row). I made some tests with the checkAndPut method of the client api, but it seems to only support comparing one value (and hence one value to be set in the put parameter). Am I understanding this correctly? If so, is there another approach to do what I need?</p>