code: public Object users() {
          return new ArrayList<Map<String, Object>>()
          {{
              add(new HashMap<String, Object>()
              {{
                  put("username","testUser1");
                  put("groups", Arrays.asList("group1"));
                  put("password","thisMechWillChange");
              }});
              add(new HashMap<String, Object>()
              {{
                  put("username","testUser2");
                  put("groups", Arrays.asList("group2"));
                  put("password","thisMechWillChange");
              }});
          }};
      }
docs: Avoiding adding extra dependencies, so using hash map.