title: android studio 3.1 Warning: The rule `-keep public class *extends java.lang.annotation.Annotation {
body: <p>i recently upgraded android studio but im not able to find the source of the following issue reported in android studio 3.1:</p>
  
  <pre><code>Warning: The rule `-keep public class *extends java.lang.annotation.Annotation {
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/xoa6T.png" rel="noreferrer"><img src="https://i.stack.imgur.com/xoa6T.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/NQM0O.png" rel="noreferrer"><img src="https://i.stack.imgur.com/NQM0O.png" alt="enter image description here"></a></p>
  
  <p>the warning seems to be cut off perhaps and missing information. but it looks like a proguard issue although i am getting this warning when building debug variant.  i checked my proguard files and i dont have a line that matches that exactly. i searched the entire project. any ideas on the root cause ?</p>