How to create an API search condition for Organization?

I am using Windchill PDMLink Release 12.0 and Datecode with CPS 12.0.0.0

I want to create an api search condition for Organization. In the code below is an api search condition created for Part Number that is using WTPart.Number and I want to develop the same structure for Organization (like 'WTPart.Organization').

QuerySpec querySpec = new QuerySpec(WTPart.class);
SearchCondition sc = new SearchCondition(WTPart.class, WTPart.NUMBER, SearchCondition.EQUAL,partNumber);
querySpec.appendWhere(sc, new int[] { 0,-1});
querySpec.appendAnd();