Using function setLayoutType it is possible to adjust fields' layout in a field group.
Following example organizes fields into 3 columns:
It is important to specify the group name as the 5th parameter of function addField (if no value is required for 4th parameter 'null' must be set).
Use setLayoutType function only when change of flow is needed. In example above it is used to start column only (e.g. TEST_Customer) and other fields follow (e.g. TEST_Priority, TEST_CaseType and TEST_Issue follow TEST_Status).