Provided is a method of and valve assembly for dumping excess fluid during retraction of a cylinder actuator. In a resource graph defining the architecture, each node or resource of the graph represents an encapsulation of functionality of one or more resources controlled by a processor or other processing entity, each edge represents a client request, and adjacent nodes of the graph represent resource dependencies. Each layer in the multi-layer density system is modeled with a different architectural resource. When disassembling the expansion card from the expansion socket, the cam is levered against a top of the expansion socket to lift out the expansion card, thereby disassembling the expansion card from the expansion socket. Controlled variables of the mathematical model are the ES target values U and inputs are the measurements y and the performance criterion J.