front/node_modules/@mui/material/modern/styles/createMuiStrictModeTheme.js

import deepmerge from '@mui/utils/deepmerge';
import createTheme from "./createTheme.js";
export default function createMuiStrictModeTheme(options, ...args) {
  return createTheme(deepmerge({
    unstable_strictMode: true
  }, options), ...args);
}