A scheme is a set of connections that exist in a given state between modules. A connection is a combination of two instances of module classes, a require interface of the client module and a normal interface of the server module.
Connections consist of:
· Client module class
· Client module instance index
· Client module require interface name
· Server module class
· Server module instance index
If the client or the server is created dynamically then in the specification the index of the instance is a negative value.