public function testAddRemove()
 {
     $this->assertFalse($this->showMapper->has('fooName'));
     $fieldDescription = $this->getFieldDescriptionMock('fooName', 'fooLabel');
     $this->showMapper->add($fieldDescription);
     $this->assertTrue($this->showMapper->has('fooName'));
     $this->showMapper->remove('fooName');
     $this->assertFalse($this->showMapper->has('fooName'));
 }