### Question:
ListBoxValues { public String getDisplayNameForValue(final String value) { return mapDisplayValuesToValues.entrySet().stream() .filter(v -> v.getValue().equals(value)) .map(Map.Entry::getKey) .findFirst() .orElse(value); } ListBoxValues(final String customPrompt,
                         final String editPrefix,
                         final ValueTester valueTester,
                         final int maxDisplayLength,
                         final boolean allowEmpty);  ListBoxValues(final String customPrompt,
                         final String editPrefix,
                         final ValueTester valueTester,
                         final int maxDisplayLength);  ListBoxValues(final String customPrompt,
                         final String editPrefix,
                         final ValueTester valueTester,
                         final boolean allowEmpty);  ListBoxValues(final String customPrompt,
                         final String editPrefix,
                         final ValueTester valueTester);  ListBoxValues(final ListBoxValues copy,
                         final boolean copyCustomValues); String getEditPrefix(); void addValues(final List<String> acceptableValues); void addValues(final Map<String, String> acceptableValues); String addCustomValue(final String newValue,
                                 final String oldValue); List<String> update(final String currentValue); List<String> getAcceptableValuesWithCustomValues(); List<String> getAcceptableValuesWithoutCustomValues(); boolean isCustomValue(final String value); String getValueForDisplayValue(final String key); String getDisplayNameForValue(final String value); String getNonCustomValueForUserString(final String userValue); String toString(); static final String EDIT_SUFFIX; }### Answer:
@Test public void testEmptyValueDisplayNameMap() { ListBoxValues values = new ListBoxValues("Constant ...", "Edit ", null); String nonMappedValue = "nonMappedValue"; assertEquals(nonMappedValue, values.getDisplayNameForValue(nonMappedValue)); }