1.10版本 无法使用WATERMARK ，报空指针。

日志样例
{"time":"2020-06-17 23:00:01.211","pushid":"pushback_send-BC110-12392212311","app":"mm"}
由于时间序列是bigint类型，用UNIX_TIMESTAMP进行转换
Flink运行日志报错：
ERROR com.dtstack.flink.sql.watermarker.CustomerWaterMarkerForLong -
java.lang.NullPointerException

建表语句：
CREATE TABLE MyTable (
time varchar ,
pushid varchar ,
app varchar ,
UNIX_TIMESTAMP(time, 'yyyy-MM-dd HH:mm:ss')*1000 bigint AS xctime ,
WATERMARK FOR xctime AS withOffset( xctime , 1000)
)
WITH (
type='kafka11',
bootstrapServers='kafka:9092',
offsetReset='latest',
topic='test_1',
groupId='flink_sql',
parallelism='4',
timezone='Asia/Shanghai',
topicIsPattern ='false',
sourcedatatype ='dt_nest'
);

CREATE TABLE MyResult(
app VARCHAR,
cnt BIGINT,
wStart timestamp
)WITH(
type ='elasticsearch6',
address ='eshost:9200',
cluster='bigdata-es5.6',
estype ='date',
index ='MyResult',
parallelism ='1',
id='0'
);

insert into MyResult
select
d.app ,
count(d.pushid) cnt ,
TUMBLE_START(d.ROWTIME, INTERVAL '3' SECOND) as wStart
from
MyTable as d
group by d.app,TUMBLE(d.ROWTIME, INTERVAL '3' SECOND);

可否提供一份完整的1.10版本 WATERMARK 语法案例。实际测试中无法使用