реагировать двойное рендера
`React intentionally remounts your components in development
to help you find bugs. You can turn off Strict Mode to opt out of the development behavior,
but we recommend keeping it on.` (Docs)
// To disable: Remove <React.StrictMode> or <StrictMode>
root.render( <React.StrictMode>
<App />
</React.StrictMode>);
// After:
root.render( <App /> );
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