public function testAddGetCorrectItems()
 {
     $fieldConfigCollection = new Tx_PtExtlist_Domain_Configuration_Data_Fields_FieldConfigCollection();
     $fieldConfigCollection->addFieldConfig(new Tx_PtExtlist_Domain_Configuration_Data_Fields_FieldConfig($this->configurationBuilderMock, 'field1', $this->aggregateSettings['field1']));
     $fieldConfigCollection->addFieldConfig(new Tx_PtExtlist_Domain_Configuration_Data_Fields_FieldConfig($this->configurationBuilderMock, 'field2', $this->aggregateSettings['field2']));
     $fieldConfig1 = $fieldConfigCollection->getFieldConfigByIdentifier('field1');
     $this->assertEquals($fieldConfig1->getIdentifier(), 'field1');
     $fieldConfig2 = $fieldConfigCollection->getFieldConfigByIdentifier('field2');
     $this->assertEquals($fieldConfig2->getIdentifier(), 'field2');
 }