model.intRule().create(<tag>,<ftag>) creates an integration rule for the frame
<ftag>.
model.intRule(<tag>).frame(<ftag>) sets the frame for the integration rule.
model.intRule(<tag>).create(<ftag>) creates an integration rule feature.
model.intRule(<tag>).feature(<ftag>).order(gporder) specifies the integration order of the integration rule.
model.intRule(<tag>).frame() returns the frame as a string.
model.intRule(<tag>).feature(<ftag>)).getAllowedPropertyValues(property) returns the set of allowed values for a property if the set is a finite set of strings; otherwise, it returns null.