code: public static UserBean unmarshallUser(Map<String, Object> source) {
          if (source == null) {
              return null;
          }
          UserBean bean = new UserBean();
          bean.setUsername(asString(source.get("username")));
          bean.setEmail(asString(source.get("email")));
          bean.setFullName(asString(source.get("fullName")));
          bean.setJoinedOn(asDate(source.get("joinedOn")));
          postMarshall(bean);
          return bean;
      }
docs: Unmarshals the given map source into a bean.
  @param source the source
  @return the user