### Question:
MessageSendRequest { public static MessageSendRequest createMultiUsersType(@NonNull List<String> targetUserIds, @NonNull List<MessageData> messages) { return new MessageSendRequest().setTargetUserIds(targetUserIds).setMessages(messages); } private  MessageSendRequest(); static MessageSendRequest createSingleUserType(@NonNull String targetUserId, @NonNull List<MessageData> messages); static MessageSendRequest createMultiUsersType(@NonNull List<String> targetUserIds, @NonNull List<MessageData> messages); static MessageSendRequest createOttType(@NonNull String ott, @NonNull List<MessageData> messages); @NonNull String toJsonString();  }### Answer:
@Test public void createMultiUsersType() { givenMessageSendRequest(MessageSendRequest.createMultiUsersType(targetUserIds, messages)); payLoadShouldBe("{\"to\":[\"targetUserId1\",\"targetUserId2\"],\"messages\":[{\"type\":\"flex\"}]}"); }