The JSimInvalidContextException is thrown whenever the user tries to call a method that cannot be invoked from the piece of code
currently being executed.
The JSimInvalidProcessStateException is thrown whenever an attempt is made to change a process's state with JSimProcess.setProcessState()
but there is not a transition between the current and the desired state in the graph of J-Sim process states.
All message classes implementing this interface assure that their receiving process can be obtained and it is a single specific process,
not a set of processes, all processes, or an unspecified process.
All message classes implementing this interface assure that their sending process can be obtained and it is a single specific process,
not a set of processes, all processes, or an unspecified process.
Process state can be one of the following constants:
New
Passive
Scheduled
Active
Blocked on Semaphore
Blocked on Message Send
Blocked on Message Received
Terminated