code: public void detachAgent(Object pVm) {
          try {
              if (pVm != null) {
                  Class clazz = pVm.getClass();
                  Method method = clazz.getMethod("detach");
                  method.setAccessible(true); // on J9 you get IllegalAccessException otherwise.
                  method.invoke(pVm);
              }
          } catch (InvocationTargetException e) {
              throw new ProcessingException("Error while detaching",e, options);
          } catch (NoSuchMethodException e) {
              throw new ProcessingException("Error while detaching",e, options);
          } catch (IllegalAccessException e) {
              throw new ProcessingException("Error while detaching",e, options);
          }
      }
docs: Detach from the virtual machine
  
  @param pVm the virtual machine to detach from