Problém s testem repository

Zdravím zkouším dělat PHP testy, a otestovat si repository. Ale pokud chci získat context metodou

\Nette\Environment::getContext();

Obdaří mě to touto chybou:

PHPUnit 3.7.21 by Sebastian Bergmann.

exception 'Nette\FatalErrorException' with message 'Cannot modify header information - headers already sent by (output started at C:\xampp\php\pear\PHPUnit\Util\Printer.php:172)' in C:\xampp\htdocs\anketa\libs\Nette\Utils\LimitedScope.php(49) : eval()'d code:377
Stack trace:
#0 [internal function]: Nette\Diagnostics\Debugger::_errorHandler(2, 'Cannot modify h...', 'C:\xampp\htdocs...', 377, Array)
#1 C:\xampp\htdocs\anketa\libs\Nette\Utils\LimitedScope.php(49) : eval()'d code(377): header('X-Frame-Options...')
#2 C:\xampp\htdocs\anketa\libs\Nette\Config\Configurator.php(206): SystemContainer->initialize()
#3 C:\xampp\htdocs\anketa\libs\Nette\common\Environment.php(330): Nette\Config\Configurator->createContainer()
#4 C:\xampp\htdocs\anketa\libs\Nette\common\Environment.php(183): Nette\Environment::loadConfig()
#5 C:\xampp\htdocs\anketa\tests\app\model\AnketaPolozkaRepositoryTest.php(24): Nette\Environment::getContext()
#6 C:\xampp\php\pear\PHPUnit\Framework\TestCase.php(828): AnketaPolozkaRepositoryTest->setUp()
#7 C:\xampp\php\pear\PHPUnit\Framework\TestResult.php(648): PHPUnit_Framework_TestCase->runBare()
#8 C:\xampp\php\pear\PHPUnit\Framework\TestCase.php(776): PHPUnit_Framework_TestResult->run(Object(AnketaPolozkaRepositoryTest))
#9 C:\xampp\php\pear\PHPUnit\Framework\TestSuite.php(775): PHPUnit_Framework_TestCase->run(Object(PHPUnit_Framework_TestResult))
#10 C:\xampp\php\pear\PHPUnit\Framework\TestSuite.php(745): PHPUnit_Framework_TestSuite->runTest(Object(AnketaPolozkaRepositoryTest), Object(PHPUnit_Framework_TestResult))
#11 C:\xampp\php\pear\PHPUnit\Framework\TestSuite.php(705): PHPUnit_Framework_TestSuite->run(Object(PHPUnit_Framework_TestResult), false, Array, Array, false)
#12 C:\xampp\php\pear\PHPUnit\TextUI\TestRunner.php(349): PHPUnit_Framework_TestSuite->run(Object(PHPUnit_Framework_TestResult), false, Array, Array, false)
#13 C:\xampp\php\pear\PHPUnit\TextUI\Command.php(176): PHPUnit_TextUI_TestRunner->doRun(Object(NetBeansSuite), Array)
#14 C:\xampp\php\pear\PHPUnit\TextUI\Command.php(129): PHPUnit_TextUI_Command->run(Array, true)
#15 C:\xampp\php\phpunit(46): PHPUnit_TextUI_Command::main()
#16 {main}

Ještě pro úplnost přidávám bootstrap.php pro testy:

use Nette\Diagnostics\Debugger;

require_once realpath( __DIR__ . '/../libs/Nette/loader.php');

Debugger::enable(Debugger::DEVELOPMENT, FALSE);
Debugger::$strictMode = TRUE;
Debugger::$maxDepth = FALSE;
Debugger::$maxLen = FALSE;

function id($a) { return $a; }

define('TEST_TEMP_DIR', __DIR__ . '/temp');

$loader = new Nette\Loaders\RobotLoader;
$loader->setCacheStorage( new Nette\Caching\Storages\FileStorage(TEST_TEMP_DIR) );
$loader->addDirectory(array(__DIR__ . '/../libs', __DIR__ . '/../app'));
$loader->register();

Mohu někoho poprosit o radu na co jsem zapomněl?

Předem děkuji.