JUnit for lambda expression and method references

[#1]

Hi Experts,

Please see below code.

 if (languageLocale == null)
         {
             localizedPopulator.populate((locale, value) -> {
                 if (StringUtils.isNotEmpty(value))
                 {
                     nameList.add(Utils.createLocalizedData(localizedPopulator.getLanguage(locale), value));
                 }
             }, source::getName); }

Any pointers on how can we cover this piece of code with JUnit? I tried couple of ways yet could not come up to a solution. Can anyone help here?