node-groupme/src/websocket/handlers/events/group/group.theme_change.ts

The only GroupMe API library that isn't a million years old.

import type { APIGroupMessage, GroupThemeChangeEvent } from 'groupme-api-types'
import type { Client } from '../../../..'

export async function themeChange(client: Client, message: APIGroupMessage, event: GroupThemeChangeEvent) {
    return
}