### Question:
MessageSendRequest { public static MessageSendRequest createSingleUserType(@NonNull String targetUserId, @NonNull List<MessageData> messages) { return new MessageSendRequest().setTargetUserId(targetUserId).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 createSingleUserType() { givenMessageSendRequest(MessageSendRequest.createSingleUserType(targetUserIds.get(0), messages)); payLoadShouldBe("{\"to\":\"targetUserId1\",\"messages\":[{\"type\":\"flex\"}]}"); }