provide informative exception when attempt is made to invoke EJB from test in standalone mode

My understanding is that I cannot invoke a method on an EJB session bean unless I am using incontainer mode (@IntegrationTest). Otherwise I get the following exception, assuming a method signature of HotelSearch#isPreviousPageAvailable().

java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.jboss.webbeans.bean.proxy.ClientProxyMethodHandler.invoke(ClientProxyMethodHandler.java:97)
at org.jboss.seam.examples.booking.action.HotelSearch_$$javassist_1.isPreviousPageAvailable(HotelSearch$$_javassist_1.java)
at org.jboss.seam.examples.booking.action.FooTest.testCallMethodOnSessionBean(FooTest.java:20)
Caused by: java.lang.NullPointerException
at org.jboss.webbeans.util.Reflections.lookupMethod(Reflections.java:514)
at org.jboss.webbeans.util.Reflections.lookupMethod(Reflections.java:496)
at org.jboss.webbeans.bean.proxy.EnterpriseBeanProxyMethodHandler.invoke(EnterpriseBeanProxyMethodHandler.java:136)
at org.jboss.seam.examples.booking.action.HotelSearch_$$javassist_0.isPreviousPageAvailable(HotelSearch$$_javassist_0.java)
... 43 more

It might helpful to turn this NullPointerException into an IllegalStateException to make it clear that it's not possible to do such a call in standalone mode.