getVisitorKeys is not part of the Prettier type definitions.

Environments:

• Prettier Version: 3.0.0
• Running Prettier via: Node
• Runtime: Node 16
• Operating System: Windows

Steps to reproduce:

import { Printer } from 'prettier';

export const printers: Record<string, Printer> = {
    'my-printer': {
        print: null as any,
        embed: null as any,
        getVisitorKeys: null as any,
    },
};

Expected behavior:

getVisitorKeys should be part of the type definitions

Actual behavior:

Code snippet errors because getVisitorKeys is missing