/**
  * @test
  */
 public function existsReturnsTrueIfTheSpecifiedKeyExistsAndIsNull()
 {
     $this->viewHelperVariableContainer->add('TYPO3\\Fluid\\ViewHelper\\NonExistent', 'someKey', null);
     $this->assertTrue($this->viewHelperVariableContainer->exists('TYPO3\\Fluid\\ViewHelper\\NonExistent', 'someKey'));
 }
 /**
  * @test
  */
 public function aSetValueCanBeRemovedAgain()
 {
     $this->viewHelperVariableContainer->add('Tx_Fluid_ViewHelper_NonExistent', 'nonExistentKey', 'value1');
     $this->viewHelperVariableContainer->remove('Tx_Fluid_ViewHelper_NonExistent', 'nonExistentKey');
     $this->assertFalse($this->viewHelperVariableContainer->exists('Tx_Fluid_ViewHelper_NonExistent', 'nonExistentKey'));
 }