protected function getRenderedValue(FieldDefinition $fieldDescription)
 {
     $fieldTypeName = $fieldDescription->getFieldType();
     $fieldTypeInstance = $this->configuration->getFieldTypeInstance($fieldTypeName, 'Xlsx');
     $unformattedFieldValue = $this->datasource->getFieldValue($fieldDescription);
     return $fieldTypeInstance->render($unformattedFieldValue);
 }
 protected function getValue(DatasourceInterface $datasource, FieldDefinition $fieldDescription, $rendererPrefix = null)
 {
     $fieldTypeName = $fieldDescription->getFieldType();
     $fieldTypeInstance = $this->configuration->getFieldTypeInstance($fieldTypeName, $rendererPrefix);
     $unformattedFieldValue = $datasource->getFieldValue($fieldDescription);
     $formattedFieldValue = $fieldTypeInstance->render($unformattedFieldValue);
     if (null !== $fieldDescription->getCallback()) {
         $formattedFieldValue = $fieldDescription->executeCallBack($formattedFieldValue, $datasource);
     }
     return $formattedFieldValue;
 }