ActivityObjectConverterUtil converts document into all possible ActivityObject
representations based on registered DocumentClassifiers and ActivityObjectConverters.
HoconConverterProcessor is a utility processor for converting any datum document
with translation rules expressed as HOCON in the classpath or at a URL.
HoconConverterUtil supports HoconConverterProcessor in converting types via application
of hocon (https://github.com/typesafehub/config/blob/master/HOCON.md) scripts