@Override
    public void visitMethodCallExpression(@NotNull PsiMethodCallExpression expression) {
      super.visitMethodCallExpression(expression);
      final PsiReferenceExpression methodExpression = expression.getMethodExpression();
      @NonNls final String methodName = methodExpression.getReferenceName();
      if (!"append".equals(methodName)) {
        return;
      }
      final PsiExpressionList argumentList = expression.getArgumentList();
      final PsiExpression[] arguments = argumentList.getExpressions();
      if (arguments.length != 1) {
        return;
      }
      final PsiExpression argument = arguments[0];
      if (!ExpressionUtils.isStringConcatenation(PsiUtil.skipParenthesizedExprDown(argument)) ||
          PsiUtil.isConstantExpression(argument)) {
        return;
      }
      final PsiMethod method = expression.resolveMethod();
      if (method == null) {
        return;
      }
      final PsiClass containingClass = method.getContainingClass();
      if (containingClass == null) {
        return;
      }
      final String className = containingClass.getQualifiedName();
      if (CommonClassNames.JAVA_LANG_STRING_BUFFER.equals(className) ||
          CommonClassNames.JAVA_LANG_STRING_BUILDER.equals(className)) {
        registerMethodCallError(expression, containingClass);
        return;
      }
      final Project project = containingClass.getProject();
      final JavaPsiFacade psiFacade = JavaPsiFacade.getInstance(project);
      final PsiClass appendableClass = psiFacade.findClass("java.lang.Appendable", GlobalSearchScope.allScope(project));
      if (appendableClass == null) {
        return;
      }
      if (!InheritanceUtil.isInheritorOrSelf(containingClass, appendableClass, true)) {
        return;
      }
      registerMethodCallError(expression, containingClass);
    }
@Override
    public void visitMethodCallExpression(@NotNull PsiMethodCallExpression expression)