An exception used to initiate the control transfer.
Methods which are declared to throw this exception are "suspendable". This
exception must always be propagated and never be caught.
Try/catch handlers are allowed:
try{ doSomething(); } catch(Throwable ex) { handleException(ex); }
Quasar instrumentation will enhance the bytecode of these methods to
support suspension and continuation of their execution; they will not catch
SuspendExecution.
This class is for internal Quasar use.
Throwing an instance of this class or a subclass of it will break things in strange ways.