title: Can't compile with jdk 11 in IntelliJ, cannot find symbol
body: <p>I set the JDK 11, it compiles until I use the new method of Java 11 <code>isBlank()</code> of a String when I use that method this error appears when compiling, I tried cleaning the JDK installations, cleaning caches from IntelliJ, rebuilding but nothing helps. The error is:</p>
  
  <p><a href="https://i.stack.imgur.com/WngUY.png" rel="noreferrer"><img src="https://i.stack.imgur.com/WngUY.png" alt="enter image description here"></a></p>