code: public static String getDefaultKey(Method method) {
          StringBuilder sb = new StringBuilder();
          getDefaultKey(method, sb);
          return sb.toString();
      }
docs: <p>Works out the non-{@link C10NKey} bundle key for method, based on its
  class FQDN and method name (plus argument types),
  e.g. <code>com.myCompany.MyClass.myMethod_String_boolean</code>
  
  @param method the method for which to work out the key(not null)
  @return method's default bundle key(not null)