title: Is it safe to use classes annotated with @RestrictTo
body: <p>I have found a good usage for RoomSQLiteQuery class, but it is annotated with @RestrictTo. And even thought IDE shows warning it compiles normally and it also looks it works normally.</p>
  
  <p>@RestrictTo only serves to give a warning when we shouldn't use something, it cannot actually forbid you to use it, right?  It will allways work in production? </p>
  
  <p>So I just wanted to check that so that I'm sure it'll work. </p>
  
  <p>No need to give advice "Don't use it, that's bad...", I'm just asking whether it's SAFE to use. (even thought you might ask me why do I need if you're really intersted :))</p>
  
  <p>EDIT: </p>
  
  <p>I have coppied the code that uses RoomSQLiteQuery (class annotated with @RestrictTo) from file that was generated by room. So if I weren't able to use than how can room use IT when generating code? Because room generated classes are in the same package.<br> 
   Also isn't it true that only using access modifiers we can restrict the usage of some class/function/whaterever?</p>