如果我在SimpleTest测试用例中使用函数的返回值，Apache就会崩溃

当我在simpletest中运行以下测试用例时，如果我使用行B，Apache就会崩溃，但如果我使用线A，一切似乎都正常。

class TestPredicateRequest extends UnitTestCase
{
    function testConstructWithPredicate()
    {
        Mock::generate("IQueryRequest");
        $oRequest = new MockIQueryRequest();
        $oPrototype = new QueryPrototype("TEST_COMMAND_STRING", 
                                         array(1 => QueryTypeConstants::CHARACTER_ID, 
                                               2 => QueryTypeConstants::CHARACTER_ID), 
                                         QueryTypeConstants::BOOLEAN);

        $oRequest->returns("GetArguments", array(2 => 102));  //only argument 2 is set.
        $oRequest->returns("GetPrototype", $oPrototype);
        $oRequest->returns("GetUnsetArguments", array(1)); //only argument 1 is unset
        $oToTest = new CharacterPredicateRequest($oRequest);
        $this->Here(101);                   //LINE A
        //$oItem = $this->Here(101);        //LINE B
    }
    function Here($CharacterID)
    {
        return $CharacterID;
    }
}

是否存储函数的返回值是控制是否发生错误的原因？

附加信息：

如果我在A行或B行之后抛出一个异常，则该异常会冒泡到顶部，并在适当的时候得到一个错误结果页。这向我表明，出于某种原因，SimpleTest框架不喜欢Line B的情况。是因为其中没有任何断言吗？

更新x2:

Apache的错误日志文件似乎很无用：

[Wed Aug 07 19:57:28.123436 2013] [mpm_winnt:notice] [pid 6908:tid 392] AH00455: Apache/2.4.4 (Win64) PHP/5.4.12 configured -- resuming normal operations
[Wed Aug 07 19:57:28.123436 2013] [mpm_winnt:notice] [pid 6908:tid 392] AH00456: Server built: Feb 22 2013 22:08:37
[Wed Aug 07 19:57:28.123436 2013] [core:notice] [pid 6908:tid 392] AH00094: Command line: 'c:''wamp''bin''apache''apache2.4.4''bin''httpd.exe -d C:/wamp/bin/apache/Apache2.4.4'
[Wed Aug 07 19:57:28.124436 2013] [mpm_winnt:notice] [pid 6908:tid 392] AH00418: Parent: Created child process 2444
[Wed Aug 07 19:57:28.863478 2013] [mpm_winnt:notice] [pid 2444:tid 284] AH00354: Child: Starting 150 worker threads.
(Crash would be here)
[Wed Aug 07 19:59:23.551038 2013] [mpm_winnt:notice] [pid 6908:tid 392] AH00428: Parent: child process 2444 exited with status 255 -- Restarting.
[Wed Aug 07 19:59:23.751049 2013] [mpm_winnt:notice] [pid 6908:tid 392] AH00455: Apache/2.4.4 (Win64) PHP/5.4.12 configured -- resuming normal operations
[Wed Aug 07 19:59:23.751049 2013] [mpm_winnt:notice] [pid 6908:tid 392] AH00456: Server built: Feb 22 2013 22:08:37
[Wed Aug 07 19:59:23.751049 2013] [core:notice] [pid 6908:tid 392] AH00094: Command line: 'c:''wamp''bin''apache''apache2.4.4''bin''httpd.exe -d C:/wamp/bin/apache/Apache2.4.4'
[Wed Aug 07 19:59:23.755050 2013] [mpm_winnt:notice] [pid 6908:tid 392] AH00418: Parent: Created child process 7288
[Wed Aug 07 19:59:24.608098 2013] [mpm_winnt:notice] [pid 7288:tid 284] AH00354: Child: Starting 150 worker threads.