List<AnnotatedParameter<X>> params = method.getParameters();
int size = params.size();
int observer = -1;
for (int i = 0; i < size; i++) {
AnnotatedParameter param = params.get(i);
for (Annotation ann : param.getAnnotations()) {
if (ann instanceof Observes) {
if (observer >= 0)
throw InjectManager.error(method.getJavaMember(), L.l("Only one param may have an @Observer"));
observer = i;