@Test
    public void testGeneratedClass() throws Exception
    {
        PluralToSingularTestMessage message = new PluralToSingularTestMessage();
        message.addError(E.A);
        assertEquals(1, message.getErrorCount());
        assertEquals(singletonList(E.A), message.getErrorList());
    }
Test for custom formats - SINGULAR & PLURAL See src/test/stg/java_bean_with_plural_to_singular_format.java.stg :
{@code <field.name; format="PC&&SINGULAR">} transforms {@code field.name} to PascalCase in singular form, for example
- {@code errors} -> {@code Error}

@author Kostiantyn Shchepanovskyi
protostuff-it/src/test/java/io/protostuff/compiler/custom/PluralToSingularIT.java