title: Using RX-Java for dependent actions and http requests
body: <p>I'm trying to use rx-java on Android to do few sequential http requests, each of which is dependent of the response of the former one.
  This does not quite fit the map() / doFinall() model and so I'm not sure what would be the best way to do this without getting into "callback hell" as well as writing concise code.</p>
  
  <p>More concretely:</p>
  
  <ol>
  <li>do http GET "/x"</li>
  <li>do http GET "/y" if (2) was successfully</li>
  <li>do calculation on the result of GET /y</li>
  </ol>
  
  <p>Any suggestions on how to go about this?</p>