* Returns a string representation of the passed field value
*
* @param opt
*/
public static String asString(Optional<Object> opt) {
final FieldType type = FieldType.forValue(opt);
if (serializers.containsKey(type)) {
return serializers.get(type).toString(opt.orNull());
} else {
throw new IllegalArgumentException("The specified type is not supported: " + type);
}