[DataGrid] Controlled selection example throws multiple selection error

[Tai-Iro]

The DataGrid example from the docs for controlled selection works fine on the page and in sand box, but throws an error to the console about requiring a paid version. The Checkbox Selection example above it does not throw an error, while also allowing multiple selections (code sandbox).
Everything functions as expected, but it still logs an error after to this change: https://github.com/mui-org/material-ui-x/pull/1823/files#diff-36939e58755c91e3693a4f18aa7796b137ba1e32f65357a940fb358286048088R247

It just appears that a free feature is suddenly not free, without any warning, despite it not being made clear in the docs and the code still running as expected.

• The issue is present in the latest release.
• I have searched the issues of this repository and believe that this is not a duplicate.

Current Behavior 😯

Selections work fine, but still logs an error.

Expected Behavior 🤔

No error is thrown, like for the Checkbox Selection example

Steps to Reproduce 🕹

Steps:

1. Run the code for the Controlled Selection example (forked code sandbox)
2. Select more than one item
3. Check log to show it still list multiple items, despite throwing an error

Context 🔦

I have an app that allows users to select items to batch delete from a database. After 4.0.0-alpha.34, that started throwing this error.

Your Environment 🌎

`npx @material-ui/envinfo`

System:
    OS: macOS 11.3
  Binaries:
    Node: 12.16.1 - ~/.nvm/versions/node/v12.16.1/bin/node
    Yarn: 1.22.4 - /usr/local/bin/yarn
    npm: 6.13.4 - ~/.nvm/versions/node/v12.16.1/bin/npm
  Browsers:
    Chrome: 91.0.4472.164
    Edge: 91.0.864.71
    Firefox: 89.0.2
    Safari: 14.1
  npmPackages:
    @material-ui/core: ^4.12.1 => 4.12.2 
    @material-ui/data-grid: ^4.0.0-alpha.34 => 4.0.0-alpha.34 
    @material-ui/styles:  4.11.4 
    @material-ui/system:  4.12.1 
    @material-ui/types:  5.1.0 
    @material-ui/utils:  4.11.2 
    @types/react:  17.0.9 
    react: ^17.0.2 => 17.0.2 
    react-dom: ^17.0.2 => 17.0.2 

Order id 💳

[Tai-Iro]

According to the comment #1823 (comment) by @m4theushw, it should allow multiple selection using checkboxes without a warning.