请根据下面的建表语句，创建一个POJO实体类，如下：CREATE TABLE `points` ( `id` BIGINT(20) NOT NULL AUTO_INCREMENT COMMENT '积分表ID', `user_id` BIGINT(20) NOT NULL COMMENT '用户ID', `username` BIGINT(20) NOT NULL COMMENT '用户名', `email` BIGINT(20) DEFAULT NULL COMMENT '邮箱', `points` TINYINT(4) NOT NULL COMMENT '积分', PRIMARY KEY (`id`), UNIQUE KEY `unique_point` (`user_id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='积分表';

根据以上建表语句，可以创建如下的POJO实体类：

public class Points {
    private Long id;
    private Long userId;
    private String username;
    private String email;
    private Integer points;

    public Points() {}

    public Points(Long userId, String username, String email, Integer points) {
        this.userId = userId;
        this.username = username;
        this.email = email;
        this.points = points;
    }

    // getter and setter methods

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public Long getUserId() {
        return userId;
    }

    public void setUserId(Long userId) {
        this.userId = userId;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public Integer getPoints() {
        return points;
    }

    public void setPoints(Integer points) {
        this.points = points;
    }
}

该实体类对应了建表语句中的所有字段，并且提供了相应的setter和getter方法。需要注意的是，建表语句中的`id`字段为自增长字段，因此在实体类中只需要提供setter和getter方法即可，无需在构造函数中初始化。