@Test
public void testMultiValue() throws Exception {
TypeManager typeManager = mock(TypeManager.class);
when(typeManager.getValueType("STRING")).thenReturn(new StringValueType());
ValueType valueType = new ListValueType(typeManager, "STRING");
FieldType fieldType = mock(FieldType.class);
when(fieldType.getValueType()).thenReturn(valueType);
HierarchicalFacetPrefixFormatter formatter = new HierarchicalFacetPrefixFormatter();
List<String> result = formatter.format(Lists.newArrayList(