1. A method to instrument application program code for a virtual machine comprising: in the course of loading an application class, which is a constituent of the application program code, to a virtual machine, determining whether the application class is an application subclass that is a direct descendent of an application superclass that is an application bootstrap class and whether the application class inherits at least one field declared in at least one of the application bootstrap class and an application superclass of the application bootstrap class; in response to determining that the application class is an application subclass of an application superclass that is an application bootstrap class and that the application class inherits a field declared in at least one of the application bootstrap class and an application superclass of the application bootstrap class, adding code to the application subclass that is a direct descendent of the application bootstrap class to declare an analysis field for use by instrumentation code that corresponds to the inherited field declared in at least one of the application bootstrap superclass and an application superclass of the bootstrap class.