public boolean mayBeInterface(PsiClass aClass) {
      final PsiReferenceList extendsList = aClass.getExtendsList();
      if (extendsList != null) {
        final PsiJavaCodeReferenceElement[] extendsElements = extendsList.getReferenceElements();
        if (extendsElements.length > 0) {
          return false;
        }
      }
      final PsiClassInitializer[] initializers = aClass.getInitializers();
      if (initializers.length > 0) {
        return false;
      }
      return allMethodsPublicAbstract(aClass) && allFieldsPublicStaticFinal(aClass) && allInnerClassesPublic(aClass);
    }
public boolean mayBeInterface(PsiClass aClass)