CL-USER(1): (defmethod test ((a integer) &key b c))
#<STANDARD-METHOD TEST (INTEGER) {39ED0F19}>
CL-USER(2): (defmethod test ((a real) &key b))
#<THREAD "interpreter" {13376A9F}>: Debugger invoked on condition of type SIMPLE-ERROR
  The method-lambda-list (A &KEY B) does not accept all of the keyword arguments defined for the generic function.