// Optimize content-type serialization depending on its state
final ContentType contentType = response.getContentTypeHolder();
if (contentType.isMimeTypeSet()) {
final DataChunk contentTypeValue = headers.setValue(Header.ContentType);
if (contentTypeValue.isNull()) {
contentType.serializeToDataChunk(contentTypeValue);
}
} else if (defaultResponseContentType != null) {
final DataChunk contenTypeValue = headers.setValue(Header.ContentType);
if (contenTypeValue.isNull()) {
final String ce = response.getCharacterEncoding();