anchor.diff:   *   variableDeclaration ';'
    * ;
    * @description Checks that valid interface declarations don't produce a compile-time error
  + * @static-warning
    * @author msyabro
    * @reviewer kaigorodov
  + * @reviewer rodionov
    */
   
   interface A default ClassA {
  
positive.code: }
  
  class ClassB implements B {
    factory B(a, b, [c = 0]) {}
    factory B.c() {}
    ClassB(a, b, c) {}
    ClassB.C() {}
  }
  
  class Class implements C, E {
    Class() {}
  }
  
  main() {
    new A();
    new B(1, 2, 3);
    new Class();
  }
  
negative.code:   set something(something);
  }
  
  interface B extends A default ClassB {
    B(a, b, [c = 0]);
    B.C();
  
  