我将创建一个课程模型，其中包含基于课程主题的字段：
教训：

@Data
public class Lesson {
    private Long id;
    private Course course;
    private String title;
    private String description;
}

字符串
课程：

@Data
@AllArgsConstructor
@NoArgsConstructor
@Builder
public class Course {
    private Long code;
    private String subject;
    private String description;
    private Set<User> users;
}

public static final Model<Lesson> LESSON_TEST_MODEL = Instancio.of(Lesson.class)
            .supply(field(Lesson::getId), () -> START_LESSON_ID.getAndSet(START_LESSON_ID.get() + DEFAULT_INCREMENT_STEP))
            .supply(field(Lesson::getCourse), () -> Instancio.of(COURSE_TEST_MODEL).create())
            .assign(given(field(Course::getSubject), field(Lesson::getTitle))
                    .set(When.is("Mathematics"), "Math Lesson")
                    .set(When.is("History"), "History Lesson")
                    .set(When.is("Literature"), "Literature Lesson")
                    .set(When.is("Physics"), "Physics Lesson")
                    .set(When.is("Computer Science"), "Computer Science Lesson"))
            .assign(given(field(Course::getSubject), field(Lesson::getDescription))
                    .set(When.is("Mathematics"), "Lesson on mathematics concepts")
                    .set(When.is("History"), "Lesson on world history")
                    .set(When.is("Literature"), "Lesson on classical literature")
                    .set(When.is("Physics"), "Lesson on fundamental physics")
                    .set(When.is("Computer Science"), "Lesson on computer programming"))
            .toModel();

型
但是提供这行代码会导致异常：

Reason: unresolved assignment expression

The following assignments could not be applied:

 -> from [field(Course, "subject")] to [field(Lesson, "title")]
 -> from [field(Course, "subject")] to [field(Lesson, "description")]

As a result, the following targets could not be assigned a value:

 -> field Lesson.description (depth=1)
 -> field Lesson.title (depth=1)

型
如何解决这个问题？