我有一门课：

import org.springframework.security.core.userdetails.UserDetails;

@Entity
@Table(name="t_user")
@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonIgnoreProperties(ignoreUnknown = true)
@Data
public class User implements Serializable, UserDetails {

@Override
    public Collection<? extends GrantedAuthority> getAuthorities() {
        return null;
    }
..
}

但我有一个编译错误：

'Many To One' attribute type should not be a container