domain: should variable domain in EventEmitter be private

[cuijinyu]

• version: Node v10.5:
• platform: Darwin Kernel Version 19.3.0:
• core module name: domain:

What steps will reproduce the bug?

The domain module overwrites the EventEmitter and mounts the domain on the EventEmitter. This causes a problem. If a third-party library mounts a variable named domain on the EventEmitter and introduces the domain module at the same time, it will cause an error.
We use the request library, which mounts the request body on EventEmitter. There is a domain field in our request body, and there is an error of domain.enter is not a function (domain is overwritten as a string at this time)

How often does it reproduce? Is there a required condition?

1. Import domain
2. Inherit the EventEmitter class
3. There is a variable named domain

What is the expected behavior?

domain should be private

What do you see instead?

Additional information

I see that the domain module no longer accepts PRs, can I submit a PR for this issue

[cuijinyu]

require('domain')
const EventEmitter = require('events').EventEmitter;

class Test extends EventEmitter {
    constructor(props) {
        super(props)
        this.domain = '123'
    }
}

const demo = new Test()

demo.emit('haha', 'haha')```

[cuijinyu]

Some third-party libraries will mount to EventEmitter. This problem will occur when a domain appears. The above is a demo