Please tell me how to use __UHEAP_CHECK to check memory allocation

I want to use __UHEAP_MARK, __UHEAP_CHECK(), and _UNHEAP_ENDMARK to check the memory allocation.
I used it like this:
__UHEAP_MARK;
CMyClass* iMyClass = CMyClass::NewL();
__UHEAP_CHECK(1);

CMyClass is a class which is defined by myself, but when I run it in debug model, there was a panic at __UHEAP_CHECK(1), I want to know whether the reason is that the parameter should not be "1", i.e,the expected number of allocated cells is not 1, or not.

And, please teach me how to use these, it's better to show me some examples which are related with self-defined class.

The last question is, as the descriptions given in the SDK, "If checking fails, the function raises a panic. Information about the failure is put into the panic category, which takes the form: "ALLOC COUNT\rExpected aaa\rAllocated bbb\rLn: ccc ddd", but my panic is not like this, it just shows "ALLOC COUNT\rExpe 1",there is not other informations, I wonder if my use of them is wrong.

PS: The NewL() func of my class CMyClass is just:
CMyClass* CMyClass::NewL()
{
CMyClass* self = NewLC();
CleanupStack::Pop();
return self;
}

CMyClass* CMyClass::NewLC()
{
CMyClass* self = new (ELeave) CMyClass;
CleanupStack::PushL(self);
self->ConstructL();
return self;
}

CMyClass* CMyClass::ConstructL()
{
// do nothing, empty
}