[Feature Request] Introduce new annotation to mark unti test classes

[hyyan]

A common need is to define proxy/mock in the same file where the unit test class lives,
If the proxy was written before the unit test class, then the following error will be thrown

!ERROR=252  (No match for method ::C:/Users/habof/AppData/Local/Temp/BBjUnitTest
1583140459530/BBjGridExWidgetCellEditorAGPopupSelectTest.bbjt::BBjGridExWidgetCe
llEditorAGPopupSelectProxy.setUp())
[15] call "C:\Users\habof\AppData\Local\Temp\BBjUnitTest1583140459530\BBjGridExW
idgetCellEditorAGPopupSelectTest.bbjt"

# BBjGridExWidgetCellEditorAGPopupSelectTest.bbjt

use ::BBjGridExWidget/BBjGridExWidgetCellEditors.bbj::BBjGridExWidgetCellEditorAGPopupSelect
use com.google.gson.JsonObject
use com.google.gson.JsonArray
use com.google.gson.JsonNull

class public BBjGridExWidgetCellEditorAGPopupSelectProxy extends BBjGridExWidgetCellEditorAGPopupSelect
    rem /**
    rem  * @override
    rem  */
    method protected static BBjNumber isBUI()
        methodret 1
    methodend
classend

class public BBjGridExWidgetCellEditorAGPopupSelectTest

    field private BBjGridExWidgetCellEditorAGPopupSelect Instance!
    
    rem @Before
    method public void setUp()
        #Instance! = new BBjGridExWidgetCellEditorAGPopupSelect()
    methodend

    rem @Test
    method public void testCellEditorNameIsSet()
        Assert.Equals(#Instance!.getCellEditorName() , "agPopupSelectCellEditor")
    methodend
    
    rem @Test
    method public void testFallbackToAGSelect()
        proxy! = new BBjGridExWidgetCellEditorAGPopupSelectProxy()
        Assert.Equals(proxy!.getCellEditorName() , "agSelectCellEditor")
    methodend    
            
    rem @After
    method public void tearDown()
        #Instance! = null()
    methodend
classend

moving the proxy to be defined at the end of the file solves the problem, but it would a nice feature if we can just introduce a new annotation (ex : @UnitTest) to mark a class as a unit test