1. A computer program product comprising one or more computer-readable media having thereon computer-executable instructions that are structured such that, when executed by one or more processors of a computing system, the computing system is caused to perform a method for allowing declarative statements of constraints to govern how a visualization of a graphical model is validated, the graphical model comprising one or more objects that include interrelationships, at least some of the objects capable of being visualized on a display, the method comprising: an act of reading a declarative constraint that comprises one or more rules that a graphical model should adhere to in order to comply with the declarative constraint; an act of identifying a graphical model that is to be subjected to the declarative constraint; an act of interpreting the declarative constraint to identify or formulate underlying code that when executed causes the one or more rules associated with the declarative constraint to be checked against the identified graphical model; and an act of causing the computing system to execute the underlying code.