private @Nullable @InspectionMessage String checkUnusedParameter(@NotNull PsiParameter parameter) {
        if (!info.isReferenced(parameter) && !UnusedSymbolUtil.isImplicitUsage(project, parameter)) {
          return JavaErrorBundle.message(parameter instanceof PsiPatternVariable ?
                                         "pattern.variable.is.not.used" : "parameter.is.not.used", parameter.getName());
        }
        return null;
      }
private @Nullable @InspectionMessage String checkUnusedParameter(@NotNull PsiParameter parameter)