Quoting from:
https://mail.openjdk.java.net/pipermail/compiler-dev/2022-April/019517.html


public class Demo {
     public static void main(String[] args) {
         var obj = new Object() {
             static void foo() {
                 System.out.println("Static method of anonymous class");
             }
         };
         obj.foo(); // Cannot replace instance qualifier with class reference
     }
}

With -Xlint:static, javac reports the following warning:

Demo.java:8: warning: [static] static method should be qualified by
type name, <anonymous Demo$1>, instead of by an expression
         obj.foo(); // Cannot replace instance qualifier with class reference
            ^
1 warning