SimpleObjectConverter hasn't implemented the writeItem method, causing it to give a null pointer exception on some tests

SimpleObjectConverter hasn't implemented the writeItem method, causing it to give a null pointer exception on some tests.
It doesn't affect major functionality right now, but can cause future errors.
The working copy of the class can be found here, possible fixes to be implemented:
https://github.com/amcarth2/openmrs-module-webservices.rest/blob/master/omod-common/src/main/java/org/openmrs/module/webservices/rest/util/SimpleObjectConverter.java