pg-cursor not work!!

[HelloKevinTian]

const { Pool } = require('pg')
const Cursor = require('pg-cursor')
const pool = new Pool({
    user: 'xxxx',
    password: 'xxxxx',
    database: 'xxxxx',
    host: 'xxxxx',
    port: 8080,
    max: 20, //default 10
})

setTimeout(async () => {
    const client = await pool.connect()
    const text = 'SELECT * FROM dim_app'
    const cursor = client.query(new Cursor(text))
    cursor.read(3, (err, rows) => {
        console.log('--->', rows, rows.length)
        cursor.close(() => {
            client.release()
        })
    });
}, 100);

HI,here is my test code.

The dim_app table which from AWS Redshift contains 100 items,I just want to test pg-cursor with getting 3 by cursor,but I always get 100 in the response.

Anyone can help? Thanks a lot.