This model extends segModelFourTypes and is the final model presented in the
segregation website which incorporates several aspects of all the other models
presented thus highlighting how different model components can be easily
incorporated into a more detailed model to explore segregation.
SegGISModel() -
Constructor for class uk.ac.ucl.casa.andrew.phd.segModelFourTypesCombined.SegGISModel
* To ensure that the current resedient is actually created
the area of interest, once the resident agent has been created
stepRestrictToForNewResident mehod is called.